diff --git a/source/lib/sysdep/os/win/mahaf.cpp b/source/lib/sysdep/os/win/mahaf.cpp
index 6f4425973e..eb800afb25 100644
--- a/source/lib/sysdep/os/win/mahaf.cpp
+++ b/source/lib/sysdep/os/win/mahaf.cpp
@@ -27,15 +27,16 @@
 #include "precompiled.h"
 #include "lib/sysdep/os/win/mahaf.h"
 
-#include "lib/sysdep/os/win/win.h"
-#include <winioctl.h>
-#include "lib/sysdep/os/win/aken/aken.h"
-#include "lib/sysdep/os/win/wutil.h"
 #include "lib/module_init.h"
 
+#include "lib/sysdep/os/win/wutil.h"
+#include <winioctl.h>
+#include "lib/sysdep/os/win/aken/aken.h"
+#include "lib/sysdep/os/win/wversion.h"
 
 static HANDLE hAken = INVALID_HANDLE_VALUE;	// handle to Aken driver
 
+
 //-----------------------------------------------------------------------------
 // ioctl wrappers
 //-----------------------------------------------------------------------------
@@ -114,7 +115,7 @@ bool mahaf_IsPhysicalMappingDangerous()
 {
 	// pre-XP versions don't prevent re-mapping pages with incompatible
 	// attributes, which may lead to disaster due to TLB corruption.
-	if(wutil_WindowsVersion() < WUTIL_VERSION_XP)
+	if(wversion_Number() < WVERSION_XP)
 		return true;
 
 	return false;
diff --git a/source/lib/sysdep/os/win/wposix/wutsname.cpp b/source/lib/sysdep/os/win/wposix/wutsname.cpp
index b8bd80a88b..85ace54c20 100644
--- a/source/lib/sysdep/os/win/wposix/wutsname.cpp
+++ b/source/lib/sysdep/os/win/wposix/wutsname.cpp
@@ -24,7 +24,7 @@
 #include "lib/sysdep/os/win/wposix/wutsname.h"
 
 #include "lib/utf8.h"
-#include "lib/sysdep/os/win/wutil.h"
+#include "lib/sysdep/os/win/wversion.h"
 
 #include "lib/sysdep/os/win/wposix/wposix_internal.h"
 
@@ -36,7 +36,7 @@ int uname(struct utsname* un)
 	GetVersionExW(&vi);
 
 	// OS implementation name
-	sprintf_s(un->sysname, ARRAY_SIZE(un->sysname), "%ls", wutil_WindowsFamily());
+	sprintf_s(un->sysname, ARRAY_SIZE(un->sysname), "%ls", wversion_Family());
 
 	// release info
 	const wchar_t* vs = vi.szCSDVersion;
@@ -45,7 +45,7 @@ int uname(struct utsname* un)
 		sprintf_s(un->release, ARRAY_SIZE(un->release), "SP %d", sp);
 
 	// version
-	sprintf_s(un->version, ARRAY_SIZE(un->version), "%ls.%lu", wutil_WindowsVersionString(), vi.dwBuildNumber & 0xFFFF);
+	sprintf_s(un->version, ARRAY_SIZE(un->version), "%ls.%lu", wversion_String(), vi.dwBuildNumber & 0xFFFF);
 
 	// node name
 	DWORD buf_size = sizeof(un->nodename);
diff --git a/source/lib/sysdep/os/win/wsnd.cpp b/source/lib/sysdep/os/win/wsnd.cpp
index 6f3c5195aa..818776086f 100644
--- a/source/lib/sysdep/os/win/wsnd.cpp
+++ b/source/lib/sysdep/os/win/wsnd.cpp
@@ -34,7 +34,7 @@
 
 #include "lib/path_util.h"
 #include "lib/sysdep/os/win/wdll_ver.h"
-#include "lib/sysdep/os/win/win.h"
+#include "lib/sysdep/os/win/wversion.h"
 #include "lib/sysdep/os/win/wutil.h"
 #include "lib/sysdep/os/win/wmi.h"
 
@@ -134,7 +134,7 @@ LibError win_get_snd_info()
 
 	// find all DLLs related to OpenAL and retrieve their versions.
 	std::wstring versionList;
-	if(wutil_WindowsVersion() < WUTIL_VERSION_VISTA)
+	if(wversion_Number() < WVERSION_VISTA)
 		wdll_ver_Append(GetDirectSoundDriverPath(), versionList);
 	StringSet dlls;	// ensures uniqueness
 	(void)add_oal_dlls_in_dir(wutil_ExecutablePath(), dlls, versionList);
diff --git a/source/lib/sysdep/os/win/wutil.cpp b/source/lib/sysdep/os/win/wutil.cpp
index 7f6d730314..e4e02d26e0 100644
--- a/source/lib/sysdep/os/win/wutil.cpp
+++ b/source/lib/sysdep/os/win/wutil.cpp
@@ -380,77 +380,6 @@ static void EnableLowFragmentationHeap()
 }
 
 
-//-----------------------------------------------------------------------------
-// version
-
-static wchar_t windowsVersionString[20];
-static size_t windowsVersion;	// see WUTIL_VERSION_*
-
-static void DetectWindowsVersion()
-{
-	// note: don't use GetVersion[Ex] because it gives the version of the
-	// emulated OS when running an app with compatibility shims enabled.
-	HKEY hKey;
-	if(RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS)
-	{
-		DWORD size = sizeof(windowsVersionString);
-		(void)RegQueryValueExW(hKey, L"CurrentVersion", 0, 0, (LPBYTE)windowsVersionString, &size);
-
-		unsigned major = 0, minor = 0;
-		// ICC 11.1.082 generates incorrect code for the following:
-		// const int ret = swscanf_s(windowsVersionString, L"%u.%u", &major, &minor);
-		std::wstringstream ss(windowsVersionString);
-		ss >> major;
-		wchar_t dot;
-		ss >> dot;
-		debug_assert(dot == '.');
-		ss >> minor;
-
-		debug_assert(4 <= major && major <= 0xFF);
-		debug_assert(minor <= 0xFF);
-		windowsVersion = (major << 8) | minor;
-
-		RegCloseKey(hKey);
-	}
-	else
-		debug_assert(0);
-}
-
-
-const wchar_t* wutil_WindowsFamily()
-{
-	debug_assert(windowsVersion != 0);
-	switch(windowsVersion)
-	{
-	case WUTIL_VERSION_2K:
-		return L"Win2k";
-	case WUTIL_VERSION_XP:
-		return L"WinXP";
-	case WUTIL_VERSION_XP64:
-		return L"WinXP64";
-	case WUTIL_VERSION_VISTA:
-		return L"Vista";
-	case WUTIL_VERSION_7:
-		return L"Win7";
-	default:
-		return L"Windows";
-	}
-}
-
-
-const wchar_t* wutil_WindowsVersionString()
-{
-	debug_assert(windowsVersionString[0] != '\0');
-	return windowsVersionString;
-}
-
-size_t wutil_WindowsVersion()
-{
-	debug_assert(windowsVersion != 0);
-	return windowsVersion;
-}
-
-
 //-----------------------------------------------------------------------------
 // Wow64
 
@@ -601,8 +530,6 @@ static LibError wutil_Init()
 
 	GetDirectories();
 
-	DetectWindowsVersion();
-
 	ImportWow64Functions();
 	DetectWow64();
 
diff --git a/source/lib/sysdep/os/win/wutil.h b/source/lib/sysdep/os/win/wutil.h
index f2161220b8..3290953340 100644
--- a/source/lib/sysdep/os/win/wutil.h
+++ b/source/lib/sysdep/os/win/wutil.h
@@ -176,26 +176,6 @@ extern const fs::wpath& wutil_ExecutablePath();
 extern const fs::wpath& wutil_AppdataPath();
 
 
-//-----------------------------------------------------------------------------
-// version
-
-extern const wchar_t* wutil_WindowsVersionString();
-
-// (same format as WINVER)
-const size_t WUTIL_VERSION_2K    = 0x0500;
-const size_t WUTIL_VERSION_XP    = 0x0501;
-const size_t WUTIL_VERSION_XP64  = 0x0502;
-const size_t WUTIL_VERSION_VISTA = 0x0600;
-const size_t WUTIL_VERSION_7     = 0x0601;
-
-/**
- * @return short textual representation of the appropriate WUTIL_VERSION
- **/
-extern const wchar_t* wutil_WindowsFamily();
-
-LIB_API size_t wutil_WindowsVersion();
-
-
 //-----------------------------------------------------------------------------
 // Wow64
 
diff --git a/source/lib/sysdep/os/win/wversion.cpp b/source/lib/sysdep/os/win/wversion.cpp
new file mode 100644
index 0000000000..732211f3d7
--- /dev/null
+++ b/source/lib/sysdep/os/win/wversion.cpp
@@ -0,0 +1,100 @@
+/* Copyright (c) 2010 Wildfire Games
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "precompiled.h"
+#include "lib/sysdep/os/win/wversion.h"
+
+#include "lib/sysdep/os/win/win.h"
+#include "lib/sysdep/os/win/winit.h"
+
+WINIT_REGISTER_EARLY_INIT(wversion_Init);
+
+
+static wchar_t windowsVersionString[20];
+static size_t windowsVersion;	// see WVERSION_*
+
+
+const wchar_t* wversion_Family()
+{
+	debug_assert(windowsVersion != 0);
+	switch(windowsVersion)
+	{
+	case WVERSION_2K:
+		return L"Win2k";
+	case WVERSION_XP:
+		return L"WinXP";
+	case WVERSION_XP64:
+		return L"WinXP64";
+	case WVERSION_VISTA:
+		return L"Vista";
+	case WVERSION_7:
+		return L"Win7";
+	default:
+		return L"Windows";
+	}
+}
+
+
+const wchar_t* wversion_String()
+{
+	debug_assert(windowsVersionString[0] != '\0');
+	return windowsVersionString;
+}
+
+size_t wversion_Number()
+{
+	debug_assert(windowsVersion != 0);
+	return windowsVersion;
+}
+
+
+static LibError wversion_Init()
+{
+	// note: don't use GetVersion[Ex] because it gives the version of the
+	// emulated OS when running an app with compatibility shims enabled.
+	HKEY hKey;
+	if(RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS)
+	{
+		DWORD size = sizeof(windowsVersionString);
+		(void)RegQueryValueExW(hKey, L"CurrentVersion", 0, 0, (LPBYTE)windowsVersionString, &size);
+
+		unsigned major = 0, minor = 0;
+		// ICC 11.1.082 generates incorrect code for the following:
+		// const int ret = swscanf_s(windowsVersionString, L"%u.%u", &major, &minor);
+		std::wstringstream ss(windowsVersionString);
+		ss >> major;
+		wchar_t dot;
+		ss >> dot;
+		debug_assert(dot == '.');
+		ss >> minor;
+
+		debug_assert(4 <= major && major <= 0xFF);
+		debug_assert(minor <= 0xFF);
+		windowsVersion = (major << 8) | minor;
+
+		RegCloseKey(hKey);
+	}
+	else
+		debug_assert(0);
+
+	return INFO::OK;
+}
diff --git a/source/lib/sysdep/os/win/wversion.h b/source/lib/sysdep/os/win/wversion.h
new file mode 100644
index 0000000000..bb9246ae66
--- /dev/null
+++ b/source/lib/sysdep/os/win/wversion.h
@@ -0,0 +1,48 @@
+/* Copyright (c) 2010 Wildfire Games
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef INCLUDED_WVERSION
+#define INCLUDED_WVERSION
+
+/**
+ * @return CurrentVersion string from registry
+ **/
+extern const wchar_t* wversion_String();
+
+// (same format as WINVER)
+const size_t WVERSION_2K    = 0x0500;
+const size_t WVERSION_XP    = 0x0501;
+const size_t WVERSION_XP64  = 0x0502;
+const size_t WVERSION_VISTA = 0x0600;
+const size_t WVERSION_7     = 0x0601;
+
+/**
+ * @return one of the above WVERSION* values
+ **/
+LIB_API size_t wversion_Number();
+
+/**
+ * @return short textual representation of the version
+ **/
+extern const wchar_t* wversion_Family();
+
+#endif	// #ifndef INCLUDED_WVERSION
diff --git a/source/ps/GameSetup/GameSetup.cpp b/source/ps/GameSetup/GameSetup.cpp
index 34c44dd51f..5706a09dee 100644
--- a/source/ps/GameSetup/GameSetup.cpp
+++ b/source/ps/GameSetup/GameSetup.cpp
@@ -31,6 +31,9 @@
 #include "lib/sysdep/cpu.h"
 #include "lib/sysdep/gfx.h"
 #include "lib/tex/tex.h"
+#if OS_WIN
+#include "lib/sysdep/os/win/wversion.h"
+#endif
 
 #include "ps/CConsole.h"
 #include "ps/CLogger.h"
@@ -334,12 +337,69 @@ static void InitScripting()
 }
 
 
-static size_t ChooseCacheSize()
+static size_t OperatingSystemFootprint()
 {
 #if OS_WIN
-	//const size_t overheadKiB = (wutil_WindowsVersion() >= WUTIL_VERSION_VISTA)? 1024 : 512;
+	switch(wversion_Number())
+	{
+	case WVERSION_2K:
+	case WVERSION_XP:
+		return 150;
+	case WVERSION_XP64:
+		return 200;
+	default:
+		debug_assert(0);
+		//fall through
+	case WVERSION_VISTA:
+		return 300;
+	case WVERSION_7:
+		return 250;
+	}
+#else
+	return 200;
 #endif
-	return 96*MiB;
+}
+
+static size_t ChooseCacheSize()
+{
+	// (all sizes in MiB)
+	const size_t total = os_cpu_MemorySize();
+	const size_t available = os_cpu_MemoryAvailable();
+	debug_assert(total >= available);
+	const size_t inUse = total-available;
+	size_t os = OperatingSystemFootprint();
+	debug_assert(total >= os/2);
+	size_t apps = (inUse > os)? (inUse - os) : 0;
+	size_t game = 400;
+	size_t cache = 200;
+
+	// plenty of memory
+	if(os + apps + game + cache < total)
+	{
+		// data is currently about 500 MiB; clamp max size to twice that
+		// to avoid unnecessarily wiping out the OS file cache.
+		cache = std::min(total - os - apps - game, (size_t)1024);
+	}
+	else	// below min-spec
+	{
+		// assume kernel+other apps will be swapped out
+		os = 9*os/10;
+		apps = 1*apps/3;
+		game = 3*game/4;
+		if(os + apps + game + cache < total)
+			cache = total - os - apps - game;
+		else
+		{
+			cache = 50;
+			debug_printf(L"Warning: memory size (%d MiB, %d used) is rather low\n", total, available);
+		}
+	}
+
+	// ensure the value will fit in size_t
+	cache = std::min(cache, (size_t)(std::numeric_limits<size_t>::max()/MiB));
+
+	debug_printf(L"Cache: %d (total: %d; available: %d)\n", cache, total, available);
+	return cache*MiB;
 }