diff --git a/dlls/winmm/winealsa/audio.c b/dlls/winmm/winealsa/audio.c
index a65dbeddf4c..056f9c1f07e 100644
--- a/dlls/winmm/winealsa/audio.c
+++ b/dlls/winmm/winealsa/audio.c
@@ -1895,47 +1895,6 @@ static DWORD wodWrite(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				wodPrepare			[internal]
- */
-static DWORD wodPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				wodUnprepare			[internal]
- */
-static DWORD wodUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			wodPause				[internal]
  */
@@ -2191,8 +2150,8 @@ DWORD WINAPI ALSA_wodMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WODM_PAUSE:	 	return wodPause		(wDevID);
     case WODM_GETPOS:	 	return wodGetPosition	(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
     case WODM_BREAKLOOP: 	return wodBreakLoop     (wDevID);
-    case WODM_PREPARE:	 	return wodPrepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-    case WODM_UNPREPARE: 	return wodUnprepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+    case WODM_PREPARE:	 	return MMSYSERR_NOTSUPPORTED;
+    case WODM_UNPREPARE: 	return MMSYSERR_NOTSUPPORTED;
     case WODM_GETVOLUME:	return wodGetVolume	(wDevID, (LPDWORD)dwParam1);
     case WODM_SETVOLUME:	return wodSetVolume	(wDevID, dwParam1);
     case WODM_RESTART:		return wodRestart	(wDevID);
@@ -3405,47 +3364,6 @@ static DWORD widAddBuffer(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				widPrepare			[internal]
- */
-static DWORD widPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEINDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				widUnprepare			[internal]
- */
-static DWORD widUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEINDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 				widStart			[internal]
  *
@@ -3601,8 +3519,8 @@ DWORD WINAPI ALSA_widMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WIDM_OPEN:	 	return widOpen		(wDevID, (LPWAVEOPENDESC)dwParam1,	dwParam2);
     case WIDM_CLOSE:	 	return widClose		(wDevID);
     case WIDM_ADDBUFFER:	return widAddBuffer	(wDevID, (LPWAVEHDR)dwParam1,		dwParam2);
-    case WIDM_PREPARE:	 	return widPrepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-    case WIDM_UNPREPARE: 	return widUnprepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+    case WIDM_PREPARE:	 	return MMSYSERR_NOTSUPPORTED;
+    case WIDM_UNPREPARE: 	return MMSYSERR_NOTSUPPORTED;
     case WIDM_GETDEVCAPS:	return widGetDevCaps	(wDevID, (LPWAVEOUTCAPSW)dwParam1,	dwParam2);
     case WIDM_GETNUMDEVS:	return widGetNumDevs	();
     case WIDM_GETPOS:	 	return widGetPosition	(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
diff --git a/dlls/winmm/winearts/audio.c b/dlls/winmm/winearts/audio.c
index 798a958a1ab..85725ceab09 100644
--- a/dlls/winmm/winearts/audio.c
+++ b/dlls/winmm/winearts/audio.c
@@ -1301,47 +1301,6 @@ static DWORD wodWrite(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				wodPrepare			[internal]
- */
-static DWORD wodPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				wodUnprepare			[internal]
- */
-static DWORD wodUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			wodPause				[internal]
  */
@@ -1543,8 +1502,8 @@ DWORD WINAPI ARTS_wodMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WODM_PAUSE:	 	return wodPause		(wDevID);
     case WODM_GETPOS:	 	return wodGetPosition	(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
     case WODM_BREAKLOOP: 	return wodBreakLoop     (wDevID);
-    case WODM_PREPARE:	 	return wodPrepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-    case WODM_UNPREPARE: 	return wodUnprepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+    case WODM_PREPARE:	 	return MMSYSERR_NOTSUPPORTED;
+    case WODM_UNPREPARE: 	return MMSYSERR_NOTSUPPORTED;
     case WODM_GETDEVCAPS:	return wodGetDevCaps	(wDevID, (LPWAVEOUTCAPSW)dwParam1,	dwParam2);
     case WODM_GETNUMDEVS:	return wodGetNumDevs	();
     case WODM_GETPITCH:	 	return MMSYSERR_NOTSUPPORTED;
@@ -1972,47 +1931,6 @@ static DWORD widAddBuffer(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				widPrepare			[internal]
- */
-static DWORD widPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEINDRV) return MMSYSERR_INVALHANDLE;
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    lpWaveHdr->dwBytesRecorded = 0;
-
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				widUnprepare			[internal]
- */
-static DWORD widUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-    if (wDevID >= MAX_WAVEINDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_INVALHANDLE;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE) {
-	TRACE("Still playing...\n");
-	return WAVERR_STILLPLAYING;
-    }
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			widStart				[internal]
  */
@@ -2076,8 +1994,8 @@ DWORD WINAPI ARTS_widMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WIDM_OPEN:	 	return widOpen		(wDevID, (LPWAVEOPENDESC)dwParam1,	dwParam2);
     case WIDM_CLOSE:		return widClose		(wDevID);
     case WIDM_ADDBUFFER:	return widAddBuffer	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_PREPARE:		return widPrepare	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_UNPREPARE:	return widUnprepare	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
+    case WIDM_PREPARE:		return MMSYSERR_NOTSUPPORTED;
+    case WIDM_UNPREPARE:	return MMSYSERR_NOTSUPPORTED;
     case WIDM_GETDEVCAPS:	return widGetDevCaps	(wDevID, (LPWAVEINCAPSW)dwParam1,	dwParam2);
     case WIDM_GETNUMDEVS:	return widGetNumDevs	();
     case WIDM_RESET:		return widReset		(wDevID);
diff --git a/dlls/winmm/wineaudioio/audio.c b/dlls/winmm/wineaudioio/audio.c
index 45cb0ab0666..322e3be8e9a 100644
--- a/dlls/winmm/wineaudioio/audio.c
+++ b/dlls/winmm/wineaudioio/audio.c
@@ -990,47 +990,6 @@ static DWORD wodWrite(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				wodPrepare			[internal]
- */
-static DWORD wodPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				wodUnprepare			[internal]
- */
-static DWORD wodUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			wodPause				[internal]
  */
@@ -1220,8 +1179,8 @@ DWORD WINAPI LIBAUDIOIO_wodMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WODM_PAUSE:	 	return wodPause		(wDevID);
     case WODM_GETPOS:	 	return wodGetPosition	(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
     case WODM_BREAKLOOP: 	return MMSYSERR_NOTSUPPORTED;
-    case WODM_PREPARE:	 	return wodPrepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-    case WODM_UNPREPARE: 	return wodUnprepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+    case WODM_PREPARE:	 	return MMSYSERR_NOTSUPPORTED;
+    case WODM_UNPREPARE: 	return MMSYSERR_NOTSUPPORTED;
     case WODM_GETDEVCAPS:	return wodGetDevCaps	(wDevID, (LPWAVEOUTCAPSW)dwParam1,	dwParam2);
     case WODM_GETNUMDEVS:	return wodGetNumDevs	();
     case WODM_GETPITCH:	 	return MMSYSERR_NOTSUPPORTED;
@@ -2091,42 +2050,6 @@ static DWORD widAddBuffer(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				widPrepare			[internal]
- */
-static DWORD widPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEINDRV) return MMSYSERR_INVALHANDLE;
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~(WHDR_INQUEUE|WHDR_DONE);
-    lpWaveHdr->dwBytesRecorded = 0;
-    TRACE("header prepared !\n");
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				widUnprepare			[internal]
- */
-static DWORD widUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-    if (wDevID >= MAX_WAVEINDRV) return MMSYSERR_INVALHANDLE;
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~(WHDR_PREPARED|WHDR_INQUEUE);
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			widStart				[internal]
  */
@@ -2214,8 +2137,8 @@ DWORD WINAPI LIBAUDIOIO_widMessage(WORD wDevID, WORD wMsg, DWORD dwUser,
     case WIDM_OPEN:		return widOpen       (wDevID, (LPWAVEOPENDESC)dwParam1, dwParam2);
     case WIDM_CLOSE:		return widClose      (wDevID);
     case WIDM_ADDBUFFER:	return widAddBuffer  (wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_PREPARE:		return widPrepare    (wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_UNPREPARE:	return widUnprepare  (wDevID, (LPWAVEHDR)dwParam1, dwParam2);
+    case WIDM_PREPARE:		return MMSYSERR_NOTSUPPORTED;
+    case WIDM_UNPREPARE:	return MMSYSERR_NOTSUPPORTED;
     case WIDM_GETDEVCAPS:	return widGetDevCaps (wDevID, (LPWAVEINCAPSW)dwParam1, dwParam2);
     case WIDM_GETNUMDEVS:	return wodGetNumDevs ();	/* same number of devices in output as in input */
     case WIDM_GETPOS:		return widGetPosition(wDevID, (LPMMTIME)dwParam1, dwParam2);
diff --git a/dlls/winmm/winejack/audio.c b/dlls/winmm/winejack/audio.c
index 6401bce1d52..1ea51bd67cb 100644
--- a/dlls/winmm/winejack/audio.c
+++ b/dlls/winmm/winejack/audio.c
@@ -1456,49 +1456,6 @@ static DWORD wodWrite(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				wodPrepare			[internal]
- */
-static DWORD wodPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-  TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-    
-  if (wDevID >= MAX_WAVEOUTDRV)
-  {
-    WARN("bad device ID !\n");
-    return MMSYSERR_BADDEVICEID;
-  }
-    
-  if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-    return WAVERR_STILLPLAYING;
-    
-  lpWaveHdr->dwFlags |= WHDR_PREPARED;
-  lpWaveHdr->dwFlags &= ~WHDR_DONE;
-  return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				wodUnprepare			[internal]
- */
-static DWORD wodUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-  TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-    
-  if (wDevID >= MAX_WAVEOUTDRV)
-  {
-    WARN("bad device ID !\n");
-    return MMSYSERR_BADDEVICEID;
-  }
-    
-  if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-    return WAVERR_STILLPLAYING;
-    
-  lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-  lpWaveHdr->dwFlags |= WHDR_DONE;
-    
-  return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			wodPause				[internal]
  */
@@ -1728,8 +1685,8 @@ DWORD WINAPI JACK_wodMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
   case WODM_PAUSE:            return wodPause(wDevID);
   case WODM_GETPOS:           return wodGetPosition(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
   case WODM_BREAKLOOP:        return wodBreakLoop(wDevID);
-  case WODM_PREPARE:          return wodPrepare(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-  case WODM_UNPREPARE:        return wodUnprepare(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+  case WODM_PREPARE:          return MMSYSERR_NOTSUPPORTED;
+  case WODM_UNPREPARE:        return MMSYSERR_NOTSUPPORTED;
   case WODM_GETDEVCAPS:       return wodGetDevCaps(wDevID, (LPWAVEOUTCAPSW)dwParam1,	dwParam2);
   case WODM_GETNUMDEVS:       return wodGetNumDevs();
   case WODM_GETPITCH:         return MMSYSERR_NOTSUPPORTED;
@@ -2287,48 +2244,6 @@ static DWORD widAddBuffer(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				widPrepare			[internal]
- */
-static DWORD widPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-		
-    if (wDevID >= MAX_WAVEINDRV) return MMSYSERR_INVALHANDLE;
-		
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-				return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    lpWaveHdr->dwBytesRecorded = 0;
-    lpWaveHdr->lpNext = NULL;
-
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				widUnprepare			[internal]
- */
-static DWORD widUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-    if (wDevID >= MAX_WAVEINDRV) {
-				WARN("bad device ID !\n");
-				return MMSYSERR_INVALHANDLE;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE) {
-				TRACE("Still playing...\n");
-				return WAVERR_STILLPLAYING;
-    }
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			widStart				[internal]
  */
@@ -2463,8 +2378,8 @@ DWORD WINAPI JACK_widMessage(WORD wDevID, WORD wMsg, DWORD dwUser,
     case WIDM_OPEN:	 	return widOpen		(wDevID, (LPWAVEOPENDESC)dwParam1,	dwParam2);
     case WIDM_CLOSE:		return widClose		(wDevID);
     case WIDM_ADDBUFFER:	return widAddBuffer	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_PREPARE:		return widPrepare	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
-    case WIDM_UNPREPARE:	return widUnprepare	(wDevID, (LPWAVEHDR)dwParam1, dwParam2);
+    case WIDM_PREPARE:		return MMSYSERR_NOTSUPPORTED;
+    case WIDM_UNPREPARE:	return MMSYSERR_NOTSUPPORTED;
     case WIDM_GETDEVCAPS:	return widGetDevCaps	(wDevID, (LPWAVEINCAPSW)dwParam1,	dwParam2);
     case WIDM_GETNUMDEVS:	return widGetNumDevs();
     case WIDM_RESET:		return widReset		(wDevID);
diff --git a/dlls/winmm/winenas/audio.c b/dlls/winmm/winenas/audio.c
index 1736e2363bb..91ecb5388f9 100644
--- a/dlls/winmm/winenas/audio.c
+++ b/dlls/winmm/winenas/audio.c
@@ -1046,47 +1046,6 @@ static DWORD wodWrite(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
     return MMSYSERR_NOERROR;
 }
 
-/**************************************************************************
- * 				wodPrepare			[internal]
- */
-static DWORD wodPrepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags |= WHDR_PREPARED;
-    lpWaveHdr->dwFlags &= ~WHDR_DONE;
-    return MMSYSERR_NOERROR;
-}
-
-/**************************************************************************
- * 				wodUnprepare			[internal]
- */
-static DWORD wodUnprepare(WORD wDevID, LPWAVEHDR lpWaveHdr, DWORD dwSize)
-{
-    TRACE("(%u, %p, %08lX);\n", wDevID, lpWaveHdr, dwSize);
-
-    if (wDevID >= MAX_WAVEOUTDRV) {
-	WARN("bad device ID !\n");
-	return MMSYSERR_BADDEVICEID;
-    }
-
-    if (lpWaveHdr->dwFlags & WHDR_INQUEUE)
-	return WAVERR_STILLPLAYING;
-
-    lpWaveHdr->dwFlags &= ~WHDR_PREPARED;
-    lpWaveHdr->dwFlags |= WHDR_DONE;
-
-    return MMSYSERR_NOERROR;
-}
-
 /**************************************************************************
  * 			wodPause				[internal]
  */
@@ -1256,8 +1215,8 @@ DWORD WINAPI NAS_wodMessage(UINT wDevID, UINT wMsg, DWORD dwUser,
     case WODM_PAUSE:	 	return wodPause		(wDevID);
     case WODM_GETPOS:	 	return wodGetPosition	(wDevID, (LPMMTIME)dwParam1, 		dwParam2);
     case WODM_BREAKLOOP: 	return wodBreakLoop     (wDevID);
-    case WODM_PREPARE:	 	return wodPrepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
-    case WODM_UNPREPARE: 	return wodUnprepare	(wDevID, (LPWAVEHDR)dwParam1, 		dwParam2);
+    case WODM_PREPARE:	 	return MMSYSERR_NOTSUPPORTED;
+    case WODM_UNPREPARE: 	return MMSYSERR_NOTSUPPORTED;
     case WODM_GETDEVCAPS:	return wodGetDevCaps	(wDevID, (LPWAVEOUTCAPSW)dwParam1,	dwParam2);
     case WODM_GETNUMDEVS:	return wodGetNumDevs	();
     case WODM_GETPITCH:	 	return MMSYSERR_NOTSUPPORTED;