diff --git a/Server.cpp b/Server.cpp
index a55f33b5..2ea54017 100644
--- a/Server.cpp
+++ b/Server.cpp
@@ -132,6 +132,10 @@ void CServer::setup(void)
 #endif
 
 	CQuery::init_mutex();
+
+#ifdef MODE_WIN
+	File::init_mutex();
+#endif
 }
 
 void CServer::destroyAllDatabases(void)
@@ -269,6 +273,10 @@ CServer::~CServer()
 	CDatabase::destroyMutex();
 #endif
 
+#ifdef MODE_WIN
+	File::destroy_mutex();
+#endif
+
 	std::cout << "Server cleanup done..." << std::endl;
 }
 
diff --git a/file.h b/file.h
index 099dd6eb..5ce270c7 100644
--- a/file.h
+++ b/file.h
@@ -20,6 +20,7 @@ const int MODE_TEMP=4;
 #endif
 #ifdef MODE_WIN
 #	include <windows.h>
+#	include "Interface/Mutex.h"
 #endif
 #ifdef MODE_LIN
 #ifndef _LARGEFILE64_SOURCE
@@ -47,6 +48,11 @@ public:
 	bool Seek(_i64 spos);
 	_i64 Size(void);
 	void Close();
+
+#ifdef _WIN32
+	static void init_mutex();
+	static void destroy_mutex();
+#endif
 	
 	std::string getFilename(void);
 	std::wstring getFilenameW(void);
@@ -61,6 +67,12 @@ private:
 	int fd;
 #endif
 	std::wstring fn;
+
+#ifdef _WIN32
+	static size_t tmp_file_index;
+	static IMutex* index_mutex;
+	static std::wstring random_prefix;
+#endif
 };
 
 bool DeleteFileInt(std::string pFilename);
diff --git a/file_win.cpp b/file_win.cpp
index 2562ed79..1fd52164 100644
--- a/file_win.cpp
+++ b/file_win.cpp
@@ -22,9 +22,14 @@
 #include "file.h"
 #include "types.h"
 #include "stringtools.h"
+#include <sstream>
 
 #ifdef MODE_WIN
 
+size_t File::tmp_file_index = 0;
+IMutex* File::index_mutex = NULL;
+std::wstring File::random_prefix;
+
 File::File()
 	: hfile(INVALID_HANDLE_VALUE)
 {
@@ -51,12 +56,16 @@ bool File::Open(std::wstring pfn, int mode)
 		dwCreationDisposition=CREATE_NEW;
 		dwDesiredAccess=GENERIC_WRITE;
 	}
-	else if( mode==MODE_APPEND
-		|| mode==MODE_TEMP )
+	else if( mode==MODE_APPEND )
 	{
 		dwCreationDisposition=OPEN_EXISTING;
 		dwDesiredAccess=GENERIC_WRITE | GENERIC_READ;
 	}
+	else if( mode==MODE_TEMP )
+	{
+		dwCreationDisposition=CREATE_NEW;
+		dwDesiredAccess=GENERIC_WRITE | GENERIC_READ;
+	}
 	else if( mode==MODE_RW 
 		|| mode==MODE_RW_SEQUENTIAL
 		|| mode==MODE_RW_CREATE
@@ -111,6 +120,8 @@ bool File::Open(std::wstring pfn, int mode)
 
 bool File::OpenTemporaryFile(const std::wstring &tmpdir)
 {
+	std::wostringstream filename;
+
 	if(tmpdir.empty())
 	{
 		wchar_t tmpp[MAX_PATH];
@@ -119,29 +130,29 @@ bool File::OpenTemporaryFile(const std::wstring &tmpdir)
 		{
 			wcscpy_s(tmpp,L"C:\\");
 		}
-
-		wchar_t filename[MAX_PATH];
-		if( GetTempFileNameW(tmpp, L"urbackup.t", 0, filename)==0 )
-		{
-			hfile=NULL;
-			int err=GetLastError();
-			return false;
-		}
-
-		return Open(filename, MODE_TEMP);
+		
+		filename << tmpp;
 	}
 	else
 	{
-		wchar_t filename[MAX_PATH];
-		if( GetTempFileNameW(tmpdir.c_str(), L"urbackup.t", 0, filename)==0 )
-		{
-			hfile=NULL;
-			int err=GetLastError();
-			return false;
-		}
+		filename << tmpdir;
 
-		return Open(filename, MODE_TEMP);
+		if(tmpdir[tmpdir.size()-1]!='\\')
+		{
+			filename << L"\\";
+		}
 	}
+
+	filename << L"urb" << random_prefix << L"-" << std::hex;
+
+	{
+		IScopedLock lock(index_mutex);
+		filename << ++tmp_file_index;
+	}
+
+	filename << L".tmp";
+
+	return Open(filename.str(), MODE_TEMP);
 }
 
 bool File::Open(void *handle)
@@ -229,4 +240,20 @@ void File::Close()
 	}
 }
 
+void File::init_mutex()
+{
+	index_mutex = Server->createMutex();
+
+	std::string rnd;
+	rnd.resize(5);
+	Server->randomFill(&rnd[0], rnd.size());
+
+	random_prefix = widen(bytesToHex(reinterpret_cast<unsigned char*>(&rnd[0]), rnd.size()));
+}
+
+void File::destroy_mutex()
+{
+	Server->destroy(index_mutex);
+}
+
 #endif