diff --git a/configure b/configure
index 0ba7318068a8582a11053ec26da3881da1e396ac..35025c18170d2c90587d032b7b1a57ecbc9a2bb4 100755
--- a/configure
+++ b/configure
@@ -20033,7 +20033,7 @@ MAKE_LIB_RULES=libs/Makelib.rules
 MAKE_PROG_RULES=programs/Makeprog.rules
 
 
-                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        ac_config_files="$ac_config_files Make.rules dlls/Makedll.rules dlls/Maketest.rules libs/Makelib.rules programs/Makeprog.rules Makefile dlls/Makefile dlls/advapi32/Makefile dlls/advapi32/tests/Makefile dlls/amstream/Makefile dlls/avicap32/Makefile dlls/avifil32/Makefile dlls/cabinet/Makefile dlls/capi2032/Makefile dlls/cards/Makefile dlls/cfgmgr32/Makefile dlls/comcat/Makefile dlls/comctl32/Makefile dlls/comctl32/tests/Makefile dlls/commdlg/Makefile dlls/crtdll/Makefile dlls/crypt32/Makefile dlls/ctl3d/Makefile dlls/d3d8/Makefile dlls/d3d9/Makefile dlls/d3dim/Makefile dlls/d3dx8/Makefile dlls/dbghelp/Makefile dlls/dciman32/Makefile dlls/ddraw/Makefile dlls/ddraw/tests/Makefile dlls/devenum/Makefile dlls/dinput/Makefile dlls/dinput8/Makefile dlls/dmband/Makefile dlls/dmcompos/Makefile dlls/dmime/Makefile dlls/dmloader/Makefile dlls/dmscript/Makefile dlls/dmstyle/Makefile dlls/dmsynth/Makefile dlls/dmusic/Makefile dlls/dmusic32/Makefile dlls/dplay/Makefile dlls/dplayx/Makefile dlls/dpnet/Makefile dlls/dpnhpast/Makefile dlls/dsound/Makefile dlls/dsound/tests/Makefile dlls/dswave/Makefile dlls/dxdiagn/Makefile dlls/dxerr8/Makefile dlls/dxerr9/Makefile dlls/dxguid/Makefile dlls/gdi/Makefile dlls/gdi/tests/Makefile dlls/glu32/Makefile dlls/glut32/Makefile dlls/hhctrl.ocx/Makefile dlls/iccvid/Makefile dlls/icmp/Makefile dlls/ifsmgr.vxd/Makefile dlls/imagehlp/Makefile dlls/imm32/Makefile dlls/iphlpapi/Makefile dlls/iphlpapi/tests/Makefile dlls/kernel/Makefile dlls/kernel/tests/Makefile dlls/lzexpand/Makefile dlls/mapi32/Makefile dlls/mapi32/tests/Makefile dlls/mmdevldr.vxd/Makefile dlls/monodebg.vxd/Makefile dlls/mpr/Makefile dlls/msacm/Makefile dlls/msacm/imaadp32/Makefile dlls/msacm/msadp32/Makefile dlls/msacm/msg711/Makefile dlls/msacm/winemp3/Makefile dlls/msdmo/Makefile dlls/mshtml/Makefile dlls/msi/Makefile dlls/msimg32/Makefile dlls/msisys/Makefile dlls/msnet32/Makefile dlls/msrle32/Makefile dlls/msvcrt/Makefile dlls/msvcrt/tests/Makefile dlls/msvcrt20/Makefile dlls/msvcrt40/Makefile dlls/msvcrtd/Makefile dlls/msvidc32/Makefile dlls/msvideo/Makefile dlls/mswsock/Makefile dlls/netapi32/Makefile dlls/netapi32/tests/Makefile dlls/newdev/Makefile dlls/ntdll/Makefile dlls/ntdll/tests/Makefile dlls/odbc32/Makefile dlls/ole32/Makefile dlls/oleacc/Makefile dlls/oleaut32/Makefile dlls/oleaut32/tests/Makefile dlls/olecli/Makefile dlls/oledlg/Makefile dlls/olepro32/Makefile dlls/olesvr/Makefile dlls/opengl32/Makefile dlls/psapi/Makefile dlls/qcap/Makefile dlls/quartz/Makefile dlls/rasapi32/Makefile dlls/richedit/Makefile dlls/rpcrt4/Makefile dlls/rpcrt4/tests/Makefile dlls/rsabase/Makefile dlls/secur32/Makefile dlls/serialui/Makefile dlls/setupapi/Makefile dlls/shdocvw/Makefile dlls/shell32/Makefile dlls/shell32/tests/Makefile dlls/shfolder/Makefile dlls/shlwapi/Makefile dlls/shlwapi/tests/Makefile dlls/snmpapi/Makefile dlls/sti/Makefile dlls/tapi32/Makefile dlls/ttydrv/Makefile dlls/twain/Makefile dlls/unicows/Makefile dlls/url/Makefile dlls/urlmon/Makefile dlls/urlmon/tests/Makefile dlls/user/Makefile dlls/user/tests/Makefile dlls/uuid/Makefile dlls/uxtheme/Makefile dlls/vdhcp.vxd/Makefile dlls/vdmdbg/Makefile dlls/version/Makefile dlls/version/tests/Makefile dlls/vmm.vxd/Makefile dlls/vnbt.vxd/Makefile dlls/vnetbios.vxd/Makefile dlls/vtdapi.vxd/Makefile dlls/vwin32.vxd/Makefile dlls/win32s/Makefile dlls/winaspi/Makefile dlls/wined3d/Makefile dlls/winedos/Makefile dlls/wineps/Makefile dlls/wininet/Makefile dlls/wininet/tests/Makefile dlls/winmm/Makefile dlls/winmm/joystick/Makefile dlls/winmm/mcianim/Makefile dlls/winmm/mciavi/Makefile dlls/winmm/mcicda/Makefile dlls/winmm/mciseq/Makefile dlls/winmm/mciwave/Makefile dlls/winmm/midimap/Makefile dlls/winmm/tests/Makefile dlls/winmm/wavemap/Makefile dlls/winmm/winealsa/Makefile dlls/winmm/winearts/Makefile dlls/winmm/wineaudioio/Makefile dlls/winmm/winejack/Makefile dlls/winmm/winenas/Makefile dlls/winmm/wineoss/Makefile dlls/winnls/Makefile dlls/winsock/Makefile dlls/winsock/tests/Makefile dlls/winspool/Makefile dlls/winspool/tests/Makefile dlls/wintab32/Makefile dlls/wintrust/Makefile dlls/wow32/Makefile dlls/wsock32/Makefile dlls/x11drv/Makefile documentation/Makefile include/Makefile libs/Makefile libs/port/Makefile libs/unicode/Makefile libs/wine/Makefile libs/wpp/Makefile loader/Makefile programs/Makefile programs/avitools/Makefile programs/clock/Makefile programs/cmdlgtst/Makefile programs/control/Makefile programs/expand/Makefile programs/notepad/Makefile programs/progman/Makefile programs/regedit/Makefile programs/regsvr32/Makefile programs/rpcss/Makefile programs/rundll32/Makefile programs/start/Makefile programs/taskmgr/Makefile programs/uninstaller/Makefile programs/view/Makefile programs/wcmd/Makefile programs/wineboot/Makefile programs/winebrowser/Makefile programs/winecfg/Makefile programs/wineconsole/Makefile programs/winedbg/Makefile programs/winefile/Makefile programs/winemenubuilder/Makefile programs/winemine/Makefile programs/winepath/Makefile programs/winetest/Makefile programs/winevdm/Makefile programs/winhelp/Makefile programs/winver/Makefile server/Makefile tools/Makefile tools/widl/Makefile tools/winapi/Makefile tools/winebuild/Makefile tools/winedump/Makefile tools/winegcc/Makefile tools/wmc/Makefile tools/wrc/Makefile"
+                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  ac_config_files="$ac_config_files Make.rules dlls/Makedll.rules dlls/Maketest.rules libs/Makelib.rules programs/Makeprog.rules Makefile dlls/Makefile dlls/advapi32/Makefile dlls/advapi32/tests/Makefile dlls/amstream/Makefile dlls/avicap32/Makefile dlls/avifil32/Makefile dlls/cabinet/Makefile dlls/capi2032/Makefile dlls/cards/Makefile dlls/cfgmgr32/Makefile dlls/comcat/Makefile dlls/comctl32/Makefile dlls/comctl32/tests/Makefile dlls/commdlg/Makefile dlls/crtdll/Makefile dlls/crypt32/Makefile dlls/ctl3d/Makefile dlls/d3d8/Makefile dlls/d3d9/Makefile dlls/d3dim/Makefile dlls/d3dx8/Makefile dlls/dbghelp/Makefile dlls/dciman32/Makefile dlls/ddraw/Makefile dlls/ddraw/tests/Makefile dlls/devenum/Makefile dlls/dinput/Makefile dlls/dinput8/Makefile dlls/dmband/Makefile dlls/dmcompos/Makefile dlls/dmime/Makefile dlls/dmloader/Makefile dlls/dmscript/Makefile dlls/dmstyle/Makefile dlls/dmsynth/Makefile dlls/dmusic/Makefile dlls/dmusic32/Makefile dlls/dplay/Makefile dlls/dplayx/Makefile dlls/dpnet/Makefile dlls/dpnhpast/Makefile dlls/dsound/Makefile dlls/dsound/tests/Makefile dlls/dswave/Makefile dlls/dxdiagn/Makefile dlls/dxerr8/Makefile dlls/dxerr9/Makefile dlls/dxguid/Makefile dlls/gdi/Makefile dlls/gdi/tests/Makefile dlls/glu32/Makefile dlls/glut32/Makefile dlls/hhctrl.ocx/Makefile dlls/iccvid/Makefile dlls/icmp/Makefile dlls/ifsmgr.vxd/Makefile dlls/imagehlp/Makefile dlls/imm32/Makefile dlls/iphlpapi/Makefile dlls/iphlpapi/tests/Makefile dlls/kernel/Makefile dlls/kernel/tests/Makefile dlls/lzexpand/Makefile dlls/mapi32/Makefile dlls/mapi32/tests/Makefile dlls/mmdevldr.vxd/Makefile dlls/monodebg.vxd/Makefile dlls/mpr/Makefile dlls/msacm/Makefile dlls/msacm/imaadp32/Makefile dlls/msacm/msadp32/Makefile dlls/msacm/msg711/Makefile dlls/msacm/winemp3/Makefile dlls/msacm/tests/Makefile dlls/msdmo/Makefile dlls/mshtml/Makefile dlls/msi/Makefile dlls/msimg32/Makefile dlls/msisys/Makefile dlls/msnet32/Makefile dlls/msrle32/Makefile dlls/msvcrt/Makefile dlls/msvcrt/tests/Makefile dlls/msvcrt20/Makefile dlls/msvcrt40/Makefile dlls/msvcrtd/Makefile dlls/msvidc32/Makefile dlls/msvideo/Makefile dlls/mswsock/Makefile dlls/netapi32/Makefile dlls/netapi32/tests/Makefile dlls/newdev/Makefile dlls/ntdll/Makefile dlls/ntdll/tests/Makefile dlls/odbc32/Makefile dlls/ole32/Makefile dlls/oleacc/Makefile dlls/oleaut32/Makefile dlls/oleaut32/tests/Makefile dlls/olecli/Makefile dlls/oledlg/Makefile dlls/olepro32/Makefile dlls/olesvr/Makefile dlls/opengl32/Makefile dlls/psapi/Makefile dlls/qcap/Makefile dlls/quartz/Makefile dlls/rasapi32/Makefile dlls/richedit/Makefile dlls/rpcrt4/Makefile dlls/rpcrt4/tests/Makefile dlls/rsabase/Makefile dlls/secur32/Makefile dlls/serialui/Makefile dlls/setupapi/Makefile dlls/shdocvw/Makefile dlls/shell32/Makefile dlls/shell32/tests/Makefile dlls/shfolder/Makefile dlls/shlwapi/Makefile dlls/shlwapi/tests/Makefile dlls/snmpapi/Makefile dlls/sti/Makefile dlls/tapi32/Makefile dlls/ttydrv/Makefile dlls/twain/Makefile dlls/unicows/Makefile dlls/url/Makefile dlls/urlmon/Makefile dlls/urlmon/tests/Makefile dlls/user/Makefile dlls/user/tests/Makefile dlls/uuid/Makefile dlls/uxtheme/Makefile dlls/vdhcp.vxd/Makefile dlls/vdmdbg/Makefile dlls/version/Makefile dlls/version/tests/Makefile dlls/vmm.vxd/Makefile dlls/vnbt.vxd/Makefile dlls/vnetbios.vxd/Makefile dlls/vtdapi.vxd/Makefile dlls/vwin32.vxd/Makefile dlls/win32s/Makefile dlls/winaspi/Makefile dlls/wined3d/Makefile dlls/winedos/Makefile dlls/wineps/Makefile dlls/wininet/Makefile dlls/wininet/tests/Makefile dlls/winmm/Makefile dlls/winmm/joystick/Makefile dlls/winmm/mcianim/Makefile dlls/winmm/mciavi/Makefile dlls/winmm/mcicda/Makefile dlls/winmm/mciseq/Makefile dlls/winmm/mciwave/Makefile dlls/winmm/midimap/Makefile dlls/winmm/tests/Makefile dlls/winmm/wavemap/Makefile dlls/winmm/winealsa/Makefile dlls/winmm/winearts/Makefile dlls/winmm/wineaudioio/Makefile dlls/winmm/winejack/Makefile dlls/winmm/winenas/Makefile dlls/winmm/wineoss/Makefile dlls/winnls/Makefile dlls/winsock/Makefile dlls/winsock/tests/Makefile dlls/winspool/Makefile dlls/winspool/tests/Makefile dlls/wintab32/Makefile dlls/wintrust/Makefile dlls/wow32/Makefile dlls/wsock32/Makefile dlls/x11drv/Makefile documentation/Makefile include/Makefile libs/Makefile libs/port/Makefile libs/unicode/Makefile libs/wine/Makefile libs/wpp/Makefile loader/Makefile programs/Makefile programs/avitools/Makefile programs/clock/Makefile programs/cmdlgtst/Makefile programs/control/Makefile programs/expand/Makefile programs/notepad/Makefile programs/progman/Makefile programs/regedit/Makefile programs/regsvr32/Makefile programs/rpcss/Makefile programs/rundll32/Makefile programs/start/Makefile programs/taskmgr/Makefile programs/uninstaller/Makefile programs/view/Makefile programs/wcmd/Makefile programs/wineboot/Makefile programs/winebrowser/Makefile programs/winecfg/Makefile programs/wineconsole/Makefile programs/winedbg/Makefile programs/winefile/Makefile programs/winemenubuilder/Makefile programs/winemine/Makefile programs/winepath/Makefile programs/winetest/Makefile programs/winevdm/Makefile programs/winhelp/Makefile programs/winver/Makefile server/Makefile tools/Makefile tools/widl/Makefile tools/winapi/Makefile tools/winebuild/Makefile tools/winedump/Makefile tools/winegcc/Makefile tools/wmc/Makefile tools/wrc/Makefile"
 
 
 cat >confcache <<\_ACEOF
@@ -20643,6 +20643,7 @@ do
   "dlls/msacm/msadp32/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msacm/msadp32/Makefile" ;;
   "dlls/msacm/msg711/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msacm/msg711/Makefile" ;;
   "dlls/msacm/winemp3/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msacm/winemp3/Makefile" ;;
+  "dlls/msacm/tests/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msacm/tests/Makefile" ;;
   "dlls/msdmo/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msdmo/Makefile" ;;
   "dlls/mshtml/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/mshtml/Makefile" ;;
   "dlls/msi/Makefile" ) CONFIG_FILES="$CONFIG_FILES dlls/msi/Makefile" ;;
diff --git a/configure.ac b/configure.ac
index 5c0542016ed9af5489b79a555c8f6bb61af5c96e..0fad74fa79894675c50518d91418c5207e0d5603 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1567,6 +1567,7 @@ dlls/msacm/imaadp32/Makefile
 dlls/msacm/msadp32/Makefile
 dlls/msacm/msg711/Makefile
 dlls/msacm/winemp3/Makefile
+dlls/msacm/tests/Makefile
 dlls/msdmo/Makefile
 dlls/mshtml/Makefile
 dlls/msi/Makefile
diff --git a/dlls/msacm/Makefile.in b/dlls/msacm/Makefile.in
index f4cb7c1376cd6b78a125501dc506da6a3e321c71..247b6816e67bd8fd368acc177485f35030fd7c48 100644
--- a/dlls/msacm/Makefile.in
+++ b/dlls/msacm/Makefile.in
@@ -22,6 +22,8 @@ C_SRCS16 = \
 
 RC_SRCS = msacm.rc
 
+SUBDIRS = tests
+
 @MAKE_DLL_RULES@
 
 ### Dependencies:
diff --git a/dlls/msacm/tests/.cvsignore b/dlls/msacm/tests/.cvsignore
new file mode 100644
index 0000000000000000000000000000000000000000..88922b89934fdfa9ce7e54d123aefe4532e9e2f3
--- /dev/null
+++ b/dlls/msacm/tests/.cvsignore
@@ -0,0 +1,3 @@
+Makefile
+msacm.ok
+testlist.c
diff --git a/dlls/msacm/tests/Makefile.in b/dlls/msacm/tests/Makefile.in
new file mode 100644
index 0000000000000000000000000000000000000000..e05eba7f14c13e0159ec1ff5922810242c9e204f
--- /dev/null
+++ b/dlls/msacm/tests/Makefile.in
@@ -0,0 +1,13 @@
+TOPSRCDIR = @top_srcdir@
+TOPOBJDIR = ../../..
+SRCDIR    = @srcdir@
+VPATH     = @srcdir@
+TESTDLL   = msacm32.dll
+IMPORTS   = msacm32
+
+CTESTS = \
+	msacm.c
+
+@MAKE_TEST_RULES@
+
+### Dependencies:
diff --git a/dlls/msacm/tests/msacm.c b/dlls/msacm/tests/msacm.c
new file mode 100644
index 0000000000000000000000000000000000000000..84879ca5882bafba1afb01f92990a8762806ed31
--- /dev/null
+++ b/dlls/msacm/tests/msacm.c
@@ -0,0 +1,384 @@
+/*
+ * Unit tests for msacm functions
+ *
+ * Copyright (c) 2004 Robert Reif
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include "wine/test.h"
+#include "windef.h"
+#include "winbase.h"
+#include "winnls.h"
+#include "mmsystem.h"
+#include "mmreg.h"
+#include "msacm.h"
+
+static BOOL CALLBACK FormatEnumProc(HACMDRIVERID hadid,
+                                    LPACMFORMATDETAILS pafd,
+                                    DWORD dwInstance,
+                                    DWORD fd)
+{
+    trace("   0x%04lx, %s\n", pafd->dwFormatTag, pafd->szFormat);
+
+    return TRUE;
+}
+
+static BOOL CALLBACK DriverEnumProc(HACMDRIVERID hadid,
+                                    DWORD dwInstance,
+                                    DWORD fdwSupport)
+{
+    MMRESULT rc;
+    ACMDRIVERDETAILS dd;
+    HACMDRIVER had;
+
+    trace("id: %p\n", hadid);
+    trace("  Supports:\n");
+    if (fdwSupport & ACMDRIVERDETAILS_SUPPORTF_ASYNC)
+        trace("    async conversions\n");
+    if (fdwSupport & ACMDRIVERDETAILS_SUPPORTF_CODEC)
+        trace("    different format conversions\n");
+    if (fdwSupport & ACMDRIVERDETAILS_SUPPORTF_CONVERTER)
+        trace("    same format conversions\n");
+    if (fdwSupport & ACMDRIVERDETAILS_SUPPORTF_FILTER)
+        trace("    filtering\n");
+
+    /* try an invalid pointer */
+    rc = acmDriverDetails(hadid, 0, 0);
+    ok(rc == MMSYSERR_INVALPARAM,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALPARAM);
+
+    /* try an invalid structure size */
+    ZeroMemory(&dd, sizeof(dd));
+    rc = acmDriverDetails(hadid, &dd, 0);
+    ok(rc == MMSYSERR_INVALPARAM,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALPARAM);
+
+    /* MSDN says this should fail but it doesn't in practice */
+    dd.cbStruct = 4;
+    rc = acmDriverDetails(hadid, &dd, 0);
+    ok(rc == MMSYSERR_NOERROR,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_NOERROR);
+
+    /* try an invalid handle */
+    dd.cbStruct = sizeof(dd);
+    rc = acmDriverDetails((HACMDRIVERID)1, &dd, 0);
+    ok(rc == MMSYSERR_INVALHANDLE,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALHANDLE);
+
+    /* try an invalid handle and pointer */
+    rc = acmDriverDetails((HACMDRIVERID)1, 0, 0);
+    ok(rc == MMSYSERR_INVALPARAM,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALPARAM);
+
+    /* try invalid details */
+    rc = acmDriverDetails(hadid, &dd, -1);
+    ok(rc == MMSYSERR_INVALFLAG,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALFLAG);
+
+    /* try valid parameters */
+    rc = acmDriverDetails(hadid, &dd, 0);
+    ok(rc == MMSYSERR_NOERROR,
+       "acmDriverDetails(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_NOERROR);
+
+    if (rc == MMSYSERR_NOERROR) {
+        trace("  Short name: %s\n", dd.szShortName);
+        trace("  Long name: %s\n", dd.szLongName);
+        trace("  Copyright: %s\n", dd.szCopyright);
+        trace("  Licensing: %s\n", dd.szLicensing);
+        trace("  Features: %s\n", dd.szFeatures);
+        trace("  Supports %lu formats\n", dd.cFormatTags);
+        trace("  Supports %lu filter formats\n", dd.cFilterTags);
+    }
+
+    /* try invalid pointer */
+    rc = acmDriverOpen(0, hadid, 0);
+    ok(rc == MMSYSERR_INVALPARAM,
+       "acmDriverOpen(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALPARAM);
+
+    /* try invalid handle */
+    rc = acmDriverOpen(&had, (HACMDRIVERID)1, 0);
+    ok(rc == MMSYSERR_INVALHANDLE,
+       "acmDriverOpen(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALHANDLE);
+
+    /* try invalid open */
+    rc = acmDriverOpen(&had, hadid, -1);
+    ok(rc == MMSYSERR_INVALFLAG,
+       "acmDriverOpen(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_INVALFLAG);
+
+    /* try valid parameters */
+    rc = acmDriverOpen(&had, hadid, 0);
+    ok(rc == MMSYSERR_NOERROR,
+       "acmDriverOpen(): rc = %08x, should be %08x\n",
+       rc, MMSYSERR_NOERROR);
+
+    if (rc == MMSYSERR_NOERROR) {
+        DWORD dwSize;
+        WAVEFORMATEX * pwfx;
+        ACMFORMATDETAILS fd;
+        HACMDRIVERID hid;
+
+        /* try bad pointer */
+        rc = acmDriverID((HACMOBJ)had, 0, 0);
+        ok(rc == MMSYSERR_INVALPARAM,
+           "acmDriverID(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALPARAM);
+
+        /* try bad handle */
+        rc = acmDriverID((HACMOBJ)1, &hid, 0);
+        ok(rc == MMSYSERR_INVALHANDLE,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALHANDLE);
+
+        /* try bad handle and pointer */
+        rc = acmDriverID((HACMOBJ)1, 0, 0);
+        ok(rc == MMSYSERR_INVALHANDLE,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALHANDLE);
+
+        /* try bad flag */
+        rc = acmDriverID((HACMOBJ)had, &hid, 1);
+        ok(rc == MMSYSERR_INVALFLAG,
+           "acmDriverID(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALFLAG);
+
+        /* try valid parameters */
+        rc = acmDriverID((HACMOBJ)had, &hid, 0);
+        ok(rc == MMSYSERR_NOERROR,
+           "acmDriverID(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_NOERROR);
+        ok(hid == hadid,
+           "acmDriverID() returned ID %08lx doesn't equal %08lx\n",
+           (DWORD)hid, (DWORD)hadid);
+
+        /* try bad pointer */
+        rc = acmMetrics((HACMOBJ)had, ACM_METRIC_MAX_SIZE_FORMAT, 0);
+        ok(rc == MMSYSERR_INVALPARAM,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALPARAM);
+
+        /* try bad handle */
+        rc = acmMetrics((HACMOBJ)1, ACM_METRIC_MAX_SIZE_FORMAT, &dwSize);
+        ok(rc == MMSYSERR_INVALHANDLE,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALHANDLE);
+
+        /* try bad pointer and handle */
+        rc = acmMetrics((HACMOBJ)1, ACM_METRIC_MAX_SIZE_FORMAT, 0);
+        ok(rc == MMSYSERR_INVALHANDLE,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_INVALHANDLE);
+
+        /* try valid parameters */
+        rc = acmMetrics((HACMOBJ)had, ACM_METRIC_MAX_SIZE_FORMAT, &dwSize);
+        ok(rc == MMSYSERR_NOERROR,
+           "acmMetrics(): rc = %08x, should be %08x\n",
+           rc, MMSYSERR_NOERROR);
+        if (rc == MMSYSERR_NOERROR) {
+            /* try bad pointer */
+            rc = acmFormatEnum(had, 0, FormatEnumProc, 0, 0);
+            ok(rc == MMSYSERR_INVALPARAM,
+               "acmFormatEnum(): rc = %08x, should be %08x\n",
+                rc, MMSYSERR_INVALPARAM);
+
+            /* try bad structure size */
+            ZeroMemory(&fd, sizeof(fd));
+            rc = acmFormatEnum(had, &fd, FormatEnumProc, 0, 0);
+            ok(rc == MMSYSERR_INVALPARAM,
+               "acmFormatEnum(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_INVALPARAM);
+
+            fd.cbStruct = sizeof(fd) - 1;
+            rc = acmFormatEnum(had, &fd, FormatEnumProc, 0, 0);
+            ok(rc == MMSYSERR_INVALPARAM,
+               "acmFormatEnum(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_INVALPARAM);
+
+            if (dwSize < sizeof(WAVEFORMATEX))
+                dwSize = sizeof(WAVEFORMATEX);
+
+            pwfx = (WAVEFORMATEX *) malloc(dwSize);
+
+            ZeroMemory(pwfx, dwSize);
+            pwfx->cbSize = LOWORD(dwSize) - sizeof(WAVEFORMATEX);
+            pwfx->wFormatTag = WAVE_FORMAT_UNKNOWN;
+
+            fd.cbStruct = sizeof(fd);
+            fd.pwfx = pwfx;
+            fd.cbwfx = dwSize;
+            fd.dwFormatTag = WAVE_FORMAT_UNKNOWN;
+
+            /* try valid parameters */
+            rc = acmFormatEnum(had, &fd, FormatEnumProc, 0, 0);
+            ok(rc == MMSYSERR_NOERROR,
+               "acmFormatEnum(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_NOERROR);
+
+            free(pwfx);
+
+            /* try invalid handle */
+            rc = acmDriverClose((HACMDRIVER)1, 0);
+            ok(rc == MMSYSERR_INVALHANDLE,
+               "acmDriverClose(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_INVALHANDLE);
+
+            /* try invalid flag */
+            rc = acmDriverClose(had, 1);
+            ok(rc == MMSYSERR_INVALFLAG,
+               "acmDriverClose(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_INVALFLAG);
+
+            /* try valid parameters */
+            rc = acmDriverClose(had, 0);
+            ok(rc == MMSYSERR_NOERROR,
+               "acmDriverClose(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_NOERROR);
+
+            /* try closing again */
+            rc = acmDriverClose(had, 0);
+            ok(rc == MMSYSERR_INVALHANDLE,
+               "acmDriverClose(): rc = %08x, should be %08x\n",
+               rc, MMSYSERR_INVALHANDLE);
+        }
+    }
+
+    return TRUE;
+}
+
+static const char * get_metric(UINT uMetric)
+{
+    switch (uMetric) {
+    case ACM_METRIC_COUNT_CODECS:
+        return "ACM_METRIC_COUNT_CODECS";
+    case ACM_METRIC_COUNT_CONVERTERS:
+        return "ACM_METRIC_COUNT_CONVERTERS";
+    case ACM_METRIC_COUNT_DISABLED:
+        return "ACM_METRIC_COUNT_DISABLED";
+    case ACM_METRIC_COUNT_DRIVERS:
+        return "ACM_METRIC_COUNT_DRIVERS";
+    case ACM_METRIC_COUNT_FILTERS:
+        return "ACM_METRIC_COUNT_FILTERS";
+    case ACM_METRIC_COUNT_HARDWARE:
+        return "ACM_METRIC_COUNT_HARDWARE";
+    case ACM_METRIC_COUNT_LOCAL_CODECS:
+        return "ACM_METRIC_COUNT_LOCAL_CODECS";
+    case ACM_METRIC_COUNT_LOCAL_CONVERTERS:
+        return "ACM_METRIC_COUNT_LOCAL_CONVERTERS";
+    case ACM_METRIC_COUNT_LOCAL_DISABLED:
+        return "ACM_METRIC_COUNT_LOCAL_DISABLED";
+    case ACM_METRIC_COUNT_LOCAL_DRIVERS:
+        return "ACM_METRIC_COUNT_LOCAL_DRIVERS";
+    case ACM_METRIC_COUNT_LOCAL_FILTERS:
+        return "ACM_METRIC_COUNT_LOCAL_FILTERS";
+    case ACM_METRIC_DRIVER_PRIORITY:
+        return "ACM_METRIC_DRIVER_PRIORITY";
+    case ACM_METRIC_DRIVER_SUPPORT:
+        return "ACM_METRIC_DRIVER_SUPPORT";
+    case ACM_METRIC_HARDWARE_WAVE_INPUT:
+        return "ACM_METRIC_HARDWARE_WAVE_INPUT";
+    case ACM_METRIC_HARDWARE_WAVE_OUTPUT:
+        return "ACM_METRIC_HARDWARE_WAVE_OUTPUT";
+    case ACM_METRIC_MAX_SIZE_FILTER:
+        return "ACM_METRIC_MAX_SIZE_FILTER";
+    case ACM_METRIC_MAX_SIZE_FORMAT:
+        return "ACM_METRIC_MAX_SIZE_FORMAT";
+    }
+
+    return "UNKNOWN";
+}
+
+static DWORD check_count(UINT uMetric)
+{
+    DWORD dwMetric;
+    MMRESULT rc;
+
+    /* try invalid result pointer */
+    rc = acmMetrics(NULL, uMetric, 0);
+    ok(rc == MMSYSERR_INVALPARAM,
+       "acmMetrics(NULL, %s, 0): rc = 0x%08x, should be 0x%08x\n",
+       get_metric(uMetric), rc, MMSYSERR_INVALPARAM);
+
+    /* try invalid handle */
+    rc = acmMetrics((HACMOBJ)1, uMetric, &dwMetric);
+    ok(rc == MMSYSERR_INVALHANDLE,
+       "acmMetrics(1, %s, %p): rc = 0x%08x, should be 0x%08x\n",
+       get_metric(uMetric), &dwMetric, rc, MMSYSERR_INVALHANDLE);
+
+    /* try invalid result pointer and handle */
+    rc = acmMetrics((HACMOBJ)1, uMetric, 0);
+    ok(rc == MMSYSERR_INVALHANDLE,
+       "acmMetrics(1, %s, 0): rc = 0x%08x, should be 0x%08x\n",
+       get_metric(uMetric), rc, MMSYSERR_INVALHANDLE);
+
+    /* try valid parameters */
+    rc = acmMetrics(NULL, uMetric, &dwMetric);
+    ok(rc == MMSYSERR_NOERROR, "acmMetrics() failed: rc = 0x%08x\n", rc);
+
+    if (rc == MMSYSERR_NOERROR)
+        trace("%s: %lu\n", get_metric(uMetric), dwMetric);
+
+    return dwMetric;
+}
+
+static void msacm_tests()
+{
+    MMRESULT rc;
+    DWORD dwCount;
+    DWORD dwACMVersion = acmGetVersion();
+
+    trace("ACM version = %u.%02u build %u%s\n",
+        HIWORD(dwACMVersion) >> 8,
+        HIWORD(dwACMVersion) & 0xff,
+        LOWORD(dwACMVersion),
+        LOWORD(dwACMVersion)  ==  0 ? " (Retail)" : "");
+
+    dwCount = check_count(ACM_METRIC_COUNT_CODECS);
+    dwCount = check_count(ACM_METRIC_COUNT_CONVERTERS);
+    dwCount = check_count(ACM_METRIC_COUNT_DISABLED);
+    dwCount = check_count(ACM_METRIC_COUNT_DRIVERS);
+    dwCount = check_count(ACM_METRIC_COUNT_FILTERS);
+    dwCount = check_count(ACM_METRIC_COUNT_HARDWARE);
+    dwCount = check_count(ACM_METRIC_COUNT_LOCAL_CODECS);
+    dwCount = check_count(ACM_METRIC_COUNT_LOCAL_CONVERTERS);
+    dwCount = check_count(ACM_METRIC_COUNT_LOCAL_DISABLED);
+    dwCount = check_count(ACM_METRIC_COUNT_LOCAL_DRIVERS);
+    dwCount = check_count(ACM_METRIC_COUNT_LOCAL_FILTERS);
+
+    trace("enabled drivers:\n");
+    rc = acmDriverEnum(DriverEnumProc, 0, 0);
+    ok(rc == MMSYSERR_NOERROR,
+      "acmDriverEnum() failed, rc=%08x, should be 0x%08x\n",
+      rc, MMSYSERR_NOERROR);
+}
+
+START_TEST(msacm)
+{
+    msacm_tests();
+}