diff --git a/Crypto/src/X509Certificate.cpp b/Crypto/src/X509Certificate.cpp
index a7a8ca087..f2263dcfd 100644
--- a/Crypto/src/X509Certificate.cpp
+++ b/Crypto/src/X509Certificate.cpp
@@ -20,6 +20,10 @@
 #include "Poco/DateTimeParser.h"
 #include <sstream>
 #include <openssl/pem.h>
+#ifdef _WIN32
+// fix for WIN32 header conflict
+#undef X509_NAME 
+#endif
 #include <openssl/x509v3.h>
 #include <openssl/err.h>
 #include <openssl/evp.h>
diff --git a/Foundation/include/Poco/Error.h b/Foundation/include/Poco/Error.h
index 1f96556b8..36f00d19e 100644
--- a/Foundation/include/Poco/Error.h
+++ b/Foundation/include/Poco/Error.h
@@ -33,10 +33,10 @@ class Foundation_API Error
 public:
 
 #ifdef POCO_OS_FAMILY_WINDOWS
-	static DWORD last();
+	static Poco::UInt32 last();
 		/// Utility function returning the last error.
 
-	static std::string getMessage(DWORD errorCode);
+	static std::string getMessage(Poco::UInt32 errorCode);
 		/// Utility function translating numeric error code to string.
 #else
 	static int last();
diff --git a/Foundation/include/Poco/Platform_WIN32.h b/Foundation/include/Poco/Platform_WIN32.h
index 67011c0de..a720d918a 100644
--- a/Foundation/include/Poco/Platform_WIN32.h
+++ b/Foundation/include/Poco/Platform_WIN32.h
@@ -21,115 +21,6 @@
 #define Foundation_Platform_WIN32_INCLUDED
 
 
-#include "Poco/UnWindows.h"
-
-
-#ifndef POCO_FORCE_MIN_WINDOWS_OS_SUPPORT
-	// Determine the real version.
-	// This setting can be forced from UnWindows.h
-	#if defined (_WIN32_WINNT_WINBLUE)
-		//Windows 8.1 _WIN32_WINNT_WINBLUE (0x0602)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WINBLUE
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WINBLUE
-	#elif defined (_WIN32_WINNT_WIN8)
-		//Windows 8	_WIN32_WINNT_WIN8 (0x0602)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WIN8
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WIN8
-	#elif defined (_WIN32_WINNT_WIN7)
-		//Windows 7	_WIN32_WINNT_WIN7 (0x0601)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WIN7
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WIN7
-	#elif defined (_WIN32_WINNT_WS08)
-		//Windows Server 2008 _WIN32_WINNT_WS08 (0x0600)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WS08
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WS08
-	#elif defined (_WIN32_WINNT_VISTA)
-		//Windows Vista	_WIN32_WINNT_VISTA (0x0600)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_VISTA
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_VISTA
-	#elif defined (_WIN32_WINNT_LONGHORN)
-		//Windows Vista	and server 2008 Development _WIN32_WINNT_LONGHORN (0x0600)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_LONGHORN
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION 0x06000000 // hardcoded, VS90 can't find NTDDI_* macros
-	#elif defined (_WIN32_WINNT_WS03)
-		//Windows Server 2003 with SP1,
-		//Windows XP with SP2 _WIN32_WINNT_WS03 (0x0502)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WS03
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WS03
-	#elif defined (_WIN32_WINNT_WINXP)
-		//Windows Server 2003, Windows XP _WIN32_WINNT_WINXP (0x0501)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WINXP
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION NTDDI_WINXP
-	#elif defined (_WIN32_WINNT_WIN2K)
-		//Windows 2000 _WIN32_WINNT_WIN2K (0x0500)
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT _WIN32_WINNT_WIN2K
-	#elif defined (WINVER)
-		// fail back on WINVER
-		#ifdef _WIN32_WINNT
-			#undef _WIN32_WINNT
-		#endif
-		#define _WIN32_WINNT WINVER
-	#elif !defined(_WIN32_WINNT)
-		// last resort = Win XP, SP1 is minimum supported
-		#define _WIN32_WINNT 0x0501
-		#ifdef NTDDI_VERSION
-			#undef NTDDI_VERSION
-		#endif
-		#define NTDDI_VERSION 0x05010100
-	#endif
-#endif // POCO_FORCE_MIN_WINDOWS_OS_SUPPORT
-
 #if defined(_MSC_VER) && !defined(POCO_MSVC_SECURE_WARNINGS) && !defined(_CRT_SECURE_NO_DEPRECATE)
 	#define _CRT_SECURE_NO_DEPRECATE
 #endif 
diff --git a/Foundation/include/Poco/Platform_WIN32_OSVER.h b/Foundation/include/Poco/Platform_WIN32_OSVER.h
new file mode 100644
index 000000000..73cdd3e34
--- /dev/null
+++ b/Foundation/include/Poco/Platform_WIN32_OSVER.h
@@ -0,0 +1,134 @@
+//
+// Platform_WIN32_OSVER.h
+//
+// $Id: //poco/1.4/Foundation/include/Poco/Platform_WIN32_OSVER.h#2 $
+//
+// Library: Foundation
+// Package: Core
+// Module:  Platform
+//
+// Platform and architecture identification macros
+// and platform-specific definitions for Windows.
+//
+// Copyright (c) 2004-2007, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_Platform_WIN32_OSVER_INCLUDED
+#define Foundation_Platform_WIN32_OSVER_INCLUDED
+
+
+#include "Poco/UnWindows.h"
+
+
+#ifndef POCO_FORCE_MIN_WINDOWS_OS_SUPPORT
+	// Determine the real version.
+	// This setting can be forced from UnWindows.h
+	#if defined (_WIN32_WINNT_WINBLUE)
+		//Windows 8.1 _WIN32_WINNT_WINBLUE (0x0602)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WINBLUE
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WINBLUE
+	#elif defined (_WIN32_WINNT_WIN8)
+		//Windows 8	_WIN32_WINNT_WIN8 (0x0602)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WIN8
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WIN8
+	#elif defined (_WIN32_WINNT_WIN7)
+		//Windows 7	_WIN32_WINNT_WIN7 (0x0601)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WIN7
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WIN7
+	#elif defined (_WIN32_WINNT_WS08)
+		//Windows Server 2008 _WIN32_WINNT_WS08 (0x0600)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WS08
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WS08
+	#elif defined (_WIN32_WINNT_VISTA)
+		//Windows Vista	_WIN32_WINNT_VISTA (0x0600)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_VISTA
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_VISTA
+	#elif defined (_WIN32_WINNT_LONGHORN)
+		//Windows Vista	and server 2008 Development _WIN32_WINNT_LONGHORN (0x0600)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_LONGHORN
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION 0x06000000 // hardcoded, VS90 can't find NTDDI_* macros
+	#elif defined (_WIN32_WINNT_WS03)
+		//Windows Server 2003 with SP1,
+		//Windows XP with SP2 _WIN32_WINNT_WS03 (0x0502)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WS03
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WS03
+	#elif defined (_WIN32_WINNT_WINXP)
+		//Windows Server 2003, Windows XP _WIN32_WINNT_WINXP (0x0501)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WINXP
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION NTDDI_WINXP
+	#elif defined (_WIN32_WINNT_WIN2K)
+		//Windows 2000 _WIN32_WINNT_WIN2K (0x0500)
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT _WIN32_WINNT_WIN2K
+	#elif defined (WINVER)
+		// fail back on WINVER
+		#ifdef _WIN32_WINNT
+			#undef _WIN32_WINNT
+		#endif
+		#define _WIN32_WINNT WINVER
+	#elif !defined(_WIN32_WINNT)
+		// last resort = Win XP, SP1 is minimum supported
+		#define _WIN32_WINNT 0x0501
+		#ifdef NTDDI_VERSION
+			#undef NTDDI_VERSION
+		#endif
+		#define NTDDI_VERSION 0x05010100
+	#endif
+#endif // POCO_FORCE_MIN_WINDOWS_OS_SUPPORT
+
+
+#endif // Foundation_Platform_WIN32_OSVER_INCLUDED
diff --git a/Foundation/include/Poco/SharedMemory_WIN32.h b/Foundation/include/Poco/SharedMemory_WIN32.h
index 79e0bbcd3..3f9efa692 100644
--- a/Foundation/include/Poco/SharedMemory_WIN32.h
+++ b/Foundation/include/Poco/SharedMemory_WIN32.h
@@ -23,7 +23,7 @@
 #include "Poco/Poco.h"
 #include "Poco/SharedMemory.h"
 #include "Poco/RefCountedObject.h"
-
+#include "Poco/UnWindows.h"
 
 namespace Poco {
 
diff --git a/Foundation/src/DirectoryWatcher.cpp b/Foundation/src/DirectoryWatcher.cpp
index 10a07368a..12149ea4a 100644
--- a/Foundation/src/DirectoryWatcher.cpp
+++ b/Foundation/src/DirectoryWatcher.cpp
@@ -15,6 +15,9 @@
 
 
 #include "Poco/DirectoryWatcher.h"
+#ifdef POCO_OS_FAMILY_WINDOWS
+#include "Poco/UnWindows.h"
+#endif
 
 
 #ifndef POCO_NO_INOTIFY
diff --git a/Foundation/src/Error.cpp b/Foundation/src/Error.cpp
index a37375be1..6a8afb705 100644
--- a/Foundation/src/Error.cpp
+++ b/Foundation/src/Error.cpp
@@ -17,6 +17,9 @@
 #include "Poco/Foundation.h"
 #include "Poco/UnicodeConverter.h"
 #include "Poco/Error.h"
+#ifdef POCO_OS_FAMILY_WINDOWS
+#include "Poco/UnWindows.h"
+#endif
 #include <string>
 #include <string.h>
 #include <errno.h>
@@ -26,13 +29,13 @@ namespace Poco {
 
 
 #ifdef POCO_OS_FAMILY_WINDOWS
-	DWORD Error::last()
+	Poco::UInt32 Error::last()
 	{
 		return GetLastError();
 	}
 
 
-	std::string Error::getMessage(DWORD errorCode)
+	std::string Error::getMessage(Poco::UInt32 errorCode)
 	{
 		std::string errMsg;
 		DWORD dwFlg = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
diff --git a/Foundation/src/Timestamp.cpp b/Foundation/src/Timestamp.cpp
index e386ad309..b547be10b 100644
--- a/Foundation/src/Timestamp.cpp
+++ b/Foundation/src/Timestamp.cpp
@@ -17,6 +17,12 @@
 #include "Poco/Timestamp.h"
 #include "Poco/Timespan.h"
 #include "Poco/Exception.h"
+#if defined(POCO_OS_FAMILY_WINDOWS)
+#include "Poco/UnWindows.h"
+#if defined(_WIN32_WCE)
+#include <cmath>
+#endif
+#endif
 #include <algorithm>
 #undef min
 #undef max
@@ -30,11 +36,6 @@
 #include <sys/time.h>
 #include <sys/times.h>
 #endif
-#elif defined(POCO_OS_FAMILY_WINDOWS)
-#include "Poco/UnWindows.h"
-#if defined(_WIN32_WCE)
-#include <cmath>
-#endif
 #endif
 
 
diff --git a/Net/src/NetworkInterface.cpp b/Net/src/NetworkInterface.cpp
index 1997e6e51..e84b49d3b 100644
--- a/Net/src/NetworkInterface.cpp
+++ b/Net/src/NetworkInterface.cpp
@@ -26,6 +26,7 @@
 #include "Poco/RefCountedObject.h"
 #include "Poco/Format.h"
 #if defined(POCO_OS_FAMILY_WINDOWS)
+	#include "Poco/Platform_WIN32_OSVER.h"
 	#if defined(POCO_WIN32_UTF8)
 		#include "Poco/UnicodeConverter.h"
 	#endif
diff --git a/NetSSL_Win/include/Poco/Net/X509Certificate.h b/NetSSL_Win/include/Poco/Net/X509Certificate.h
index fe0a0208b..26629b3b2 100644
--- a/NetSSL_Win/include/Poco/Net/X509Certificate.h
+++ b/NetSSL_Win/include/Poco/Net/X509Certificate.h
@@ -24,6 +24,7 @@
 #include "Poco/DateTime.h"
 #include <set>
 #include <istream>
+#include <Poco/UnWindows.h>
 #include <wincrypt.h>
 
 
diff --git a/Util/include/Poco/Util/WinRegistryConfiguration.h b/Util/include/Poco/Util/WinRegistryConfiguration.h
index 64bc8cc7f..1d3f879b9 100644
--- a/Util/include/Poco/Util/WinRegistryConfiguration.h
+++ b/Util/include/Poco/Util/WinRegistryConfiguration.h
@@ -23,6 +23,7 @@
 #include "Poco/Util/Util.h"
 #include "Poco/Util/AbstractConfiguration.h"
 #include "Poco/String.h"
+#include "Poco/UnWindows.h"
 
 
 namespace Poco {