Index: src/ch/MainWnd.cpp
===================================================================
diff -u -N -r328d5100c7f464a4b1fbbbd7ccfa07bf2aaae2cf -rc7c8665bac90c5701e577cd11acfad86538b8063
--- src/ch/MainWnd.cpp	(.../MainWnd.cpp)	(revision 328d5100c7f464a4b1fbbbd7ccfa07bf2aaae2cf)
+++ src/ch/MainWnd.cpp	(.../MainWnd.cpp)	(revision c7c8665bac90c5701e577cd11acfad86538b8063)
@@ -2085,14 +2085,21 @@
 
 void CMainWnd::OnPopupRegisterdll() 
 {
+	CString strPath;
+	CCopyHandlerApp* pApp = GetApp();
+	if(pApp)
+	{
+		strPath = pApp->GetProgramPath();
+		strPath += _T("\\");
+	}
+
 #ifdef _WIN64
-	HRESULT hResult = RegisterShellExtDll(_T("chext64.dll"), true);
+	strPath += _T("chext64.dll");
 #else
-	HRESULT hResult = RegisterShellExtDll(_T("chext.dll"), true);
+	strPath += _T("chext.dll");
 #endif
-	if(SUCCEEDED(hResult))
-		MsgBox(IDS_REGISTEROK_STRING, MB_ICONINFORMATION | MB_OK);
-	else
+	HRESULT hResult = RegisterShellExtDll(strPath, true);
+	if(FAILED(hResult))
 	{
 		TCHAR szStr[256], szText[768];
 		FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, hResult, 0, szStr, 256, NULL);
@@ -2101,18 +2108,28 @@
 		_sntprintf(szText, 768, GetResManager()->LoadString(IDS_REGISTERERR_STRING), hResult, szStr);
 		AfxMessageBox(szText, MB_ICONERROR | MB_OK);
 	}
+	else if(hResult == S_OK)
+		MsgBox(IDS_REGISTEROK_STRING, MB_ICONINFORMATION | MB_OK);
 }
 
 void CMainWnd::OnPopupUnregisterdll() 
 {
+	CString strPath;
+	CCopyHandlerApp* pApp = GetApp();
+	if(pApp)
+	{
+		strPath = pApp->GetProgramPath();
+		strPath += _T("\\");
+	}
+
 #ifdef _WIN64
-	HRESULT hResult = RegisterShellExtDll(_T("chext64.dll"), false);
+	strPath += _T("chext64.dll");
 #else
-	HRESULT hResult = RegisterShellExtDll(_T("chext.dll"), false);
+	strPath += _T("chext.dll");
 #endif
-	if(SUCCEEDED(hResult))
-		MsgBox(IDS_UNREGISTEROK_STRING, MB_ICONINFORMATION | MB_OK);
-	else
+
+	HRESULT hResult = RegisterShellExtDll(strPath, false);
+	if(FAILED(hResult))
 	{
 		TCHAR szStr[256], szText[768];
 		FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, hResult, 0, szStr, 256, NULL);
@@ -2121,6 +2138,8 @@
 		_sntprintf(szText, 768, GetResManager()->LoadString(IDS_UNREGISTERERR_STRING), hResult, szStr);
 		AfxMessageBox(szText, MB_ICONERROR | MB_OK);
 	}
+	else if(hResult == S_OK)
+		MsgBox(IDS_UNREGISTEROK_STRING, MB_ICONINFORMATION | MB_OK);
 }
 
 void CMainWnd::PrepareToExit()
Index: src/ch/register.cpp
===================================================================
diff -u -N -re667429b5d9008da845b7bd146a2581c38551dfd -rc7c8665bac90c5701e577cd11acfad86538b8063
--- src/ch/register.cpp	(.../register.cpp)	(revision e667429b5d9008da845b7bd146a2581c38551dfd)
+++ src/ch/register.cpp	(.../register.cpp)	(revision c7c8665bac90c5701e577cd11acfad86538b8063)
@@ -27,27 +27,53 @@
 
 HRESULT RegisterShellExtDll(LPCTSTR lpszPath, bool bRegister)
 {
-	HRESULT hResult = CoInitialize(NULL);
-	if(FAILED(hResult))
-		return hResult;
-
-	HRESULT (STDAPICALLTYPE *pfn)(void);
-	HINSTANCE hMod = LoadLibrary(lpszPath);	// load the dll
-	if(hMod == NULL)
-		hResult = HRESULT_FROM_WIN32(GetLastError());
-	if(SUCCEEDED(hResult) && !hMod)
-		hResult = E_FAIL;
+	// first try - load dll and register it manually.
+	HRESULT hResult = S_OK;
+	// if failed - try by loading extension manually (would fail on vista when running as user)
+	hResult = CoInitialize(NULL);
 	if(SUCCEEDED(hResult))
 	{
-		(FARPROC&)pfn = GetProcAddress(hMod, (bRegister ? "DllRegisterServer" : "DllUnregisterServer"));
-		if(pfn == NULL)
+		HRESULT (STDAPICALLTYPE *pfn)(void);
+		HINSTANCE hMod = LoadLibrary(lpszPath);	// load the dll
+		if(hMod == NULL)
+			hResult = HRESULT_FROM_WIN32(GetLastError());
+		if(SUCCEEDED(hResult) && !hMod)
 			hResult = E_FAIL;
 		if(SUCCEEDED(hResult))
-			hResult = (*pfn)();
+		{
+			(FARPROC&)pfn = GetProcAddress(hMod, (bRegister ? "DllRegisterServer" : "DllUnregisterServer"));
+			if(pfn == NULL)
+				hResult = E_FAIL;
+			if(SUCCEEDED(hResult))
+				hResult = (*pfn)();
 
-		CoFreeLibrary(hMod);
+			CoFreeLibrary(hMod);
+		}
+		CoUninitialize();
 	}
-	CoUninitialize();
 
+	// if previous operation failed (ie. vista system) - try running regsvr32 with elevated privileges
+	if(SCODE_CODE(hResult) == ERROR_ACCESS_DENIED)
+	{
+		hResult = S_FALSE;
+		// try with regsvr32
+		SHELLEXECUTEINFO sei;
+		memset(&sei, 0, sizeof(sei));
+		sei.cbSize = sizeof(sei);
+		sei.fMask = SEE_MASK_UNICODE;
+		sei.lpVerb = _T("runas");
+		sei.lpFile = _T("regsvr32.exe");
+		CString strParams;
+		if(bRegister)
+			strParams = CString(_T(" \"")) + lpszPath + CString(_T("\""));
+		else
+			strParams = CString(_T("/u \"")) + lpszPath + CString(_T("\""));
+		sei.lpParameters = strParams;
+		sei.nShow = SW_SHOW;
+
+		if(!ShellExecuteEx(&sei))
+			hResult = E_FAIL;
+	}
+
 	return hResult;
 }