diff --git a/stepmania/src/arch/ArchHooks/ArchHooks.h b/stepmania/src/arch/ArchHooks/ArchHooks.h
index 76b97e96d9..e13cc2460b 100644
--- a/stepmania/src/arch/ArchHooks/ArchHooks.h
+++ b/stepmania/src/arch/ArchHooks/ArchHooks.h
@@ -42,6 +42,12 @@ public:
 	/* Re-exec the game.  If this is implemented, it doesn't return. */
 	virtual void RestartProgram() { }
 
+	/* Call this to temporarily enter a high-priority or realtime scheduling (depending
+	 * on the implementation) mode.  This is used to improve timestamp accuracy.  Do as
+	 * little as possible in this mode; hanging in it might hang the system entirely. */
+	virtual void EnterTimeCriticalSection() { }
+	virtual void ExitTimeCriticalSection() { }
+
 protected:
 	virtual void MessageBoxErrorPrivate( CString sMessage, CString ID ) { printf("Error: %s\n", sMessage.c_str()); }
 	virtual void MessageBoxOKPrivate( CString sMessage, CString ID ) {}
diff --git a/stepmania/src/arch/ArchHooks/ArchHooks_Win32.cpp b/stepmania/src/arch/ArchHooks/ArchHooks_Win32.cpp
index e85e07433f..6e8e4eeb67 100644
--- a/stepmania/src/arch/ArchHooks/ArchHooks_Win32.cpp
+++ b/stepmania/src/arch/ArchHooks/ArchHooks_Win32.cpp
@@ -12,9 +12,16 @@
 #include "archutils/win32/RestartProgram.h"
 #include "ProductInfo.h"
 
+#include "RageThreads.h"
 ArchHooks_Win32::ArchHooks_Win32()
 {
 	SetUnhandledExceptionFilter(CrashHandler);
+	TimeCritMutex = new RageMutex;
+}
+
+ArchHooks_Win32::~ArchHooks_Win32()
+{
+	delete TimeCritMutex;
 }
 
 void ArchHooks_Win32::DumpDebugInfo()
@@ -180,9 +187,24 @@ void ArchHooks_Win32::RestartProgram()
 	Win32RestartProgram();
 }
 
+void ArchHooks_Win32::EnterTimeCriticalSection()
+{
+	TimeCritMutex->Lock();
+
+	OldThreadPriority = GetThreadPriority( GetCurrentThread() );
+	SetThreadPriority( GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL );
+}
+
+void ArchHooks_Win32::ExitTimeCriticalSection()
+{
+	SetThreadPriority( GetCurrentThread(), OldThreadPriority );
+	OldThreadPriority = 0;
+	TimeCritMutex->Unlock();
+}
+
 
 /*
- * Copyright (c) 2002-2003 by the person(s) listed below.  All rights reserved.
+ * Copyright (c) 2002-2004 by the person(s) listed below.  All rights reserved.
  *
  * Glenn Maynard
  * Chris Danford
diff --git a/stepmania/src/arch/ArchHooks/ArchHooks_Win32.h b/stepmania/src/arch/ArchHooks/ArchHooks_Win32.h
index 6ffc814ee8..9fa927b4a1 100644
--- a/stepmania/src/arch/ArchHooks/ArchHooks_Win32.h
+++ b/stepmania/src/arch/ArchHooks/ArchHooks_Win32.h
@@ -2,16 +2,24 @@
 #define ARCH_HOOKS_WIN32_H
 
 #include "ArchHooks.h"
+class RageMutex;
+
 class ArchHooks_Win32: public ArchHooks
 {
 public:
     ArchHooks_Win32();
+    ~ArchHooks_Win32();
     void DumpDebugInfo();
     void MessageBoxOKPrivate( CString sMessage, CString ID );
 	void MessageBoxErrorPrivate( CString error, CString ID );
     MessageBoxResult MessageBoxAbortRetryIgnorePrivate( CString sMessage, CString ID );
     MessageBoxResult MessageBoxRetryCancelPrivate( CString sMessage, CString ID );
 	void RestartProgram();
+
+	int OldThreadPriority;
+	RageMutex *TimeCritMutex;
+	void EnterTimeCriticalSection();
+	void ExitTimeCriticalSection();
 };
 
 #undef ARCH_HOOKS