diff --git a/reactos/lib/advapi32/reg/reg.c b/reactos/lib/advapi32/reg/reg.c
index 7391a22b3b2..0f495f4e461 100644
--- a/reactos/lib/advapi32/reg/reg.c
+++ b/reactos/lib/advapi32/reg/reg.c
@@ -264,7 +264,6 @@ OpenCurrentConfigKey (PHANDLE KeyHandle)
 LONG STDCALL
 RegCloseKey (HKEY hKey)
 {
-  LONG ErrorCode;
   NTSTATUS Status;
 
   /* don't close null handle or a pseudo handle */
@@ -276,9 +275,7 @@ RegCloseKey (HKEY hKey)
   Status = NtClose (hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -444,7 +441,6 @@ RegCreateKeyExA (HKEY hKey,
   UNICODE_STRING ClassString;
   OBJECT_ATTRIBUTES Attributes;
   HANDLE ParentKey;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   DPRINT("RegCreateKeyExA() called\n");
@@ -454,9 +450,7 @@ RegCreateKeyExA (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
   DPRINT("ParentKey %x\n", (ULONG)ParentKey);
 
@@ -488,9 +482,7 @@ RegCreateKeyExA (HKEY hKey,
   DPRINT("Status %x\n", Status);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -517,7 +509,6 @@ RegCreateKeyExW (HKEY hKey,
   UNICODE_STRING ClassString;
   OBJECT_ATTRIBUTES Attributes;
   HANDLE ParentKey;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   DPRINT("RegCreateKeyExW() called\n");
@@ -527,9 +518,7 @@ RegCreateKeyExW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError(Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError(Status);
     }
   DPRINT("ParentKey %x\n", (ULONG)ParentKey);
 
@@ -551,9 +540,7 @@ RegCreateKeyExW (HKEY hKey,
   DPRINT("Status %x\n", Status);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -618,15 +605,12 @@ RegDeleteKeyA (HKEY hKey,
   HANDLE ParentKey;
   HANDLE TargetKey;
   NTSTATUS Status;
-  LONG ErrorCode;
 
   Status = MapDefaultKey (&ParentKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   RtlCreateUnicodeStringFromAsciiz (&SubKeyName,
@@ -643,18 +627,14 @@ RegDeleteKeyA (HKEY hKey,
   RtlFreeUnicodeString (&SubKeyName);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtDeleteKey (TargetKey);
   NtClose (TargetKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError(Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError(Status);
     }
 
   return ERROR_SUCCESS;
@@ -675,15 +655,12 @@ RegDeleteKeyW (HKEY hKey,
   HANDLE ParentKey;
   HANDLE TargetKey;
   NTSTATUS Status;
-  LONG ErrorCode;
 
   Status = MapDefaultKey (&ParentKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   RtlInitUnicodeString (&SubKeyName,
@@ -698,18 +675,14 @@ RegDeleteKeyW (HKEY hKey,
 		      &ObjectAttributes);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtDeleteKey (TargetKey);
   NtClose (TargetKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -727,16 +700,13 @@ RegDeleteValueA (HKEY hKey,
 {
   UNICODE_STRING ValueName;
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   Status = MapDefaultKey (&KeyHandle,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   RtlCreateUnicodeStringFromAsciiz (&ValueName,
@@ -746,9 +716,7 @@ RegDeleteValueA (HKEY hKey,
   RtlFreeUnicodeString (&ValueName);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -766,16 +734,13 @@ RegDeleteValueW (HKEY hKey,
 {
   UNICODE_STRING ValueName;
   NTSTATUS Status;
-  LONG ErrorCode;
   HANDLE KeyHandle;
 
   Status = MapDefaultKey (&KeyHandle,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   RtlInitUnicodeString (&ValueName,
@@ -785,9 +750,7 @@ RegDeleteValueW (HKEY hKey,
 			     &ValueName);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -880,16 +843,13 @@ RegEnumKeyExA (HKEY hKey,
 
 	if ((lpClass) && (!lpcbClass))
 	{
-		SetLastError (ERROR_INVALID_PARAMETER);
 		return ERROR_INVALID_PARAMETER;
 	}
 
 	Status = MapDefaultKey(&KeyHandle, hKey);
 	if (!NT_SUCCESS(Status))
 	{
-		ErrorCode = RtlNtStatusToDosError (Status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (Status);
 	}
 
 	if (*lpcbName > 0)
@@ -923,7 +883,6 @@ RegEnumKeyExA (HKEY hKey,
 	KeyInfo = RtlAllocateHeap (ProcessHeap, 0, BufferSize);
 	if (KeyInfo == NULL)
 	{
-		SetLastError (ERROR_OUTOFMEMORY);
 		return ERROR_OUTOFMEMORY;
 	}
 
@@ -1010,11 +969,6 @@ RegEnumKeyExA (HKEY hKey,
 		0,
 		KeyInfo);
 
-	if (ErrorCode != ERROR_SUCCESS)
-	{
-		SetLastError(ErrorCode);
-	}
-
 	return ErrorCode;
 }
 
@@ -1052,9 +1006,7 @@ RegEnumKeyExW (HKEY hKey,
 			 hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (*lpcbName > 0)
@@ -1089,7 +1041,6 @@ RegEnumKeyExW (HKEY hKey,
 			     BufferSize);
   if (KeyInfo == NULL)
     {
-      SetLastError (ERROR_OUTOFMEMORY);
       return ERROR_OUTOFMEMORY;
     }
 
@@ -1162,11 +1113,6 @@ RegEnumKeyExW (HKEY hKey,
 	       0,
 	       KeyInfo);
 
-  if (ErrorCode != ERROR_SUCCESS)
-    {
-      SetLastError(ErrorCode);
-    }
-
   return ErrorCode;
 }
 
@@ -1194,10 +1140,7 @@ RegEnumValueA( HKEY hKey, DWORD index, LPSTR value, LPDWORD val_count,
 	status = MapDefaultKey (&KeyHandle, hKey);
 	if (!NT_SUCCESS(status))
 	{
-		LONG ErrorCode;
-		ErrorCode =	RtlNtStatusToDosError (status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (status);
 	}
 
     total_size = info_size + (MAX_PATH + 1) * sizeof(WCHAR);
@@ -1321,10 +1264,7 @@ RegEnumValueW( HKEY hKey, DWORD index, LPWSTR value, PDWORD val_count,
 	status = MapDefaultKey (&KeyHandle, hKey);
 	if (!NT_SUCCESS(status))
 	{
-		LONG ErrorCode;
-		ErrorCode = RtlNtStatusToDosError (status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (status);
 	}
 
     total_size = info_size + (MAX_PATH + 1) * sizeof(WCHAR);
@@ -1399,7 +1339,6 @@ LONG STDCALL
 RegFlushKey(HKEY hKey)
 {
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
@@ -1411,17 +1350,13 @@ RegFlushKey(HKEY hKey)
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtFlushKey (KeyHandle);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -1440,12 +1375,10 @@ RegGetKeySecurity(HKEY hKey,
 		  LPDWORD lpcbSecurityDescriptor)
 {
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
     {
-      SetLastError(ERROR_INVALID_HANDLE);
       return ERROR_INVALID_HANDLE;
     }
 
@@ -1454,9 +1387,7 @@ RegGetKeySecurity(HKEY hKey,
   if (!NT_SUCCESS(Status))
     {
       DPRINT("MapDefaultKey() failed (Status %lx)\n", Status);
-      ErrorCode = RtlNtStatusToDosError(Status);
-      SetLastError(ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtQuerySecurityObject(KeyHandle,
@@ -1467,9 +1398,7 @@ RegGetKeySecurity(HKEY hKey,
   if (!NT_SUCCESS(Status))
     {
       DPRINT("NtQuerySecurityObject() failed (Status %lx)\n", Status);
-      ErrorCode = RtlNtStatusToDosError(Status);
-      SetLastError(ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -1521,12 +1450,10 @@ RegLoadKeyW (HKEY hKey,
   UNICODE_STRING FileName;
   UNICODE_STRING KeyName;
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
     {
-      SetLastError(ERROR_INVALID_HANDLE);
       return ERROR_INVALID_HANDLE;
     }
 
@@ -1534,9 +1461,7 @@ RegLoadKeyW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (!RtlDosPathNameToNtPathName_U ((LPWSTR)lpFile,
@@ -1544,7 +1469,6 @@ RegLoadKeyW (HKEY hKey,
 				     NULL,
 				     NULL))
     {
-      SetLastError (ERROR_BAD_PATHNAME);
       return ERROR_BAD_PATHNAME;
     }
 
@@ -1570,9 +1494,7 @@ RegLoadKeyW (HKEY hKey,
 
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -1720,7 +1642,6 @@ RegOpenKeyExA (HKEY hKey,
 	OBJECT_ATTRIBUTES ObjectAttributes;
 	UNICODE_STRING SubKeyString;
 	HANDLE KeyHandle;
-	LONG ErrorCode;
 	NTSTATUS Status;
 
 	DPRINT("RegOpenKeyExA hKey 0x%x lpSubKey %s ulOptions 0x%x samDesired 0x%x phkResult %p\n",
@@ -1729,9 +1650,7 @@ RegOpenKeyExA (HKEY hKey,
 	Status = MapDefaultKey (&KeyHandle, hKey);
 	if (!NT_SUCCESS(Status))
 	{
-		ErrorCode = RtlNtStatusToDosError (Status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (Status);
 	}
 
 	RtlCreateUnicodeStringFromAsciiz (&SubKeyString, (LPSTR)lpSubKey);
@@ -1745,9 +1664,7 @@ RegOpenKeyExA (HKEY hKey,
 	RtlFreeUnicodeString (&SubKeyString);
 	if (!NT_SUCCESS(Status))
 	{
-		ErrorCode = RtlNtStatusToDosError (Status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (Status);
 	}
 
 	return ERROR_SUCCESS;
@@ -1769,7 +1686,6 @@ RegOpenKeyExW (HKEY hKey,
 	OBJECT_ATTRIBUTES ObjectAttributes;
 	UNICODE_STRING SubKeyString;
 	HANDLE KeyHandle;
-	LONG ErrorCode;
 	NTSTATUS Status;
 
 	DPRINT("RegOpenKeyExW hKey 0x%x lpSubKey %S ulOptions 0x%x samDesired 0x%x phkResult %p\n",
@@ -1778,9 +1694,7 @@ RegOpenKeyExW (HKEY hKey,
 	Status = MapDefaultKey (&KeyHandle, hKey);
 	if (!NT_SUCCESS(Status))
 	{
-		ErrorCode = RtlNtStatusToDosError (Status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (Status);
 	}
 
 	if (lpSubKey != NULL)
@@ -1798,9 +1712,7 @@ RegOpenKeyExW (HKEY hKey,
 
 	if (!NT_SUCCESS(Status))
 	{
-		ErrorCode = RtlNtStatusToDosError (Status);
-		SetLastError (ErrorCode);
-		return ErrorCode;
+		return RtlNtStatusToDosError (Status);
 	}
 
 	return ERROR_SUCCESS;
@@ -1893,12 +1805,11 @@ RegQueryInfoKeyW (HKEY hKey,
   ULONG ClassLength = 0;
   HANDLE KeyHandle;
   NTSTATUS Status;
-  LONG ErrorCode = ERROR_SUCCESS;
   ULONG Length;
+  LONG ErrorCode = ERROR_SUCCESS;
 
   if ((lpClass) && (!lpcbClass))
     {
-      SetLastError(ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -1906,9 +1817,7 @@ RegQueryInfoKeyW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (lpClass != NULL)
@@ -1928,7 +1837,6 @@ RegQueryInfoKeyW (HKEY hKey,
 				  FullInfoSize);
       if (FullInfo == NULL)
 	{
-	  SetLastError (ERROR_OUTOFMEMORY);
 	  return ERROR_OUTOFMEMORY;
 	}
 
@@ -1957,9 +1865,7 @@ RegQueryInfoKeyW (HKEY hKey,
 		       FullInfo);
 	}
 
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   DPRINT("SubKeys %d\n", FullInfo->SubKeys);
@@ -2016,9 +1922,7 @@ RegQueryInfoKeyW (HKEY hKey,
 			  FullInfo);
 	    }
 
-	  ErrorCode = RtlNtStatusToDosError(Status);
-	  SetLastError(ErrorCode);
-	  return ErrorCode;
+	  return RtlNtStatusToDosError (Status);
 	}
     }
 
@@ -2048,11 +1952,6 @@ RegQueryInfoKeyW (HKEY hKey,
 		   FullInfo);
     }
 
-  if (ErrorCode != ERROR_SUCCESS)
-    {
-      SetLastError (ErrorCode);
-    }
-
   return ErrorCode;
 }
 
@@ -2201,10 +2100,10 @@ RegQueryValueExW (HKEY hKey,
   PKEY_VALUE_PARTIAL_INFORMATION ValueInfo;
   UNICODE_STRING ValueName;
   NTSTATUS Status;
-  LONG ErrorCode = ERROR_SUCCESS;
   ULONG BufferSize;
   ULONG ResultSize;
   HANDLE KeyHandle;
+  LONG ErrorCode = ERROR_SUCCESS;
   ULONG MaxCopy = lpcbData != NULL && lpData != NULL ? *lpcbData : 0;
 
   DPRINT("hKey 0x%X  lpValueName %S  lpData 0x%X  lpcbData %d\n",
@@ -2214,14 +2113,11 @@ RegQueryValueExW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (lpData != NULL && lpcbData == NULL)
     {
-      SetLastError (ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2233,7 +2129,6 @@ RegQueryValueExW (HKEY hKey,
 			       BufferSize);
   if (ValueInfo == NULL)
     {
-      SetLastError(ERROR_OUTOFMEMORY);
       return ERROR_OUTOFMEMORY;
     }
 
@@ -2253,7 +2148,6 @@ RegQueryValueExW (HKEY hKey,
   else if (!NT_SUCCESS(Status))
     {
       ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
       MaxCopy = 0;
       if (lpcbData != NULL)
 	{
@@ -2332,7 +2226,6 @@ RegQueryValueExA (HKEY hKey,
 
   if (lpData != NULL && lpcbData == NULL)
     {
-      SetLastError(ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2345,7 +2238,6 @@ RegQueryValueExA (HKEY hKey,
 					  ValueData.MaximumLength);
       if (!ValueData.Buffer)
 	{
-	  SetLastError(ERROR_OUTOFMEMORY);
 	  return ERROR_OUTOFMEMORY;
 	}
     }
@@ -2441,7 +2333,6 @@ RegQueryValueA (HKEY hKey,
   if (lpValue != NULL &&
       lpcbValue == NULL)
     {
-      SetLastError(ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2470,7 +2361,6 @@ RegQueryValueA (HKEY hKey,
 				      ValueSize);
       if (Value.Buffer == NULL)
 	{
-	  SetLastError(ERROR_OUTOFMEMORY);
 	  return ERROR_OUTOFMEMORY;
 	}
     }
@@ -2533,9 +2423,7 @@ RegQueryValueW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (lpSubKey != NULL &&
@@ -2553,9 +2441,7 @@ RegQueryValueW (HKEY hKey,
 			  &ObjectAttributes);
       if (!NT_SUCCESS(Status))
 	{
-	  ErrorCode = RtlNtStatusToDosError (Status);
-	  SetLastError (ErrorCode);
-	  return ErrorCode;
+	  return RtlNtStatusToDosError (Status);
 	}
       CloseRealKey = TRUE;
     }
@@ -2636,7 +2522,6 @@ RegReplaceKeyW (HKEY hKey,
   BOOLEAN CloseRealKey;
   HANDLE RealKeyHandle;
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
@@ -2648,9 +2533,7 @@ RegReplaceKeyW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   /* Open the real key */
@@ -2668,9 +2551,7 @@ RegReplaceKeyW (HKEY hKey,
 			  &KeyObjectAttributes);
       if (!NT_SUCCESS(Status))
 	{
-	  ErrorCode = RtlNtStatusToDosError (Status);
-	  SetLastError (ErrorCode);
-	  return ErrorCode;
+	  return RtlNtStatusToDosError (Status);
 	}
       CloseRealKey = TRUE;
     }
@@ -2690,7 +2571,6 @@ RegReplaceKeyW (HKEY hKey,
 	{
 	  NtClose (RealKeyHandle);
 	}
-      SetLastError (ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2711,7 +2591,6 @@ RegReplaceKeyW (HKEY hKey,
 	{
 	  NtClose (RealKeyHandle);
 	}
-      SetLastError (ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2735,9 +2614,7 @@ RegReplaceKeyW (HKEY hKey,
 
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -2785,7 +2662,6 @@ RegRestoreKeyW (HKEY hKey,
   UNICODE_STRING FileName;
   HANDLE FileHandle;
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
@@ -2797,9 +2673,7 @@ RegRestoreKeyW (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (!RtlDosPathNameToNtPathName_U ((LPWSTR)lpFile,
@@ -2807,7 +2681,6 @@ RegRestoreKeyW (HKEY hKey,
 				     NULL,
 				     NULL))
     {
-      SetLastError (ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2826,9 +2699,7 @@ RegRestoreKeyW (HKEY hKey,
   RtlFreeUnicodeString (&FileName);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtRestoreKey (KeyHandle,
@@ -2837,9 +2708,7 @@ RegRestoreKeyW (HKEY hKey,
   NtClose (FileHandle);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -2887,15 +2756,12 @@ RegSaveKeyW (HKEY hKey,
   HANDLE FileHandle;
   HANDLE KeyHandle;
   NTSTATUS Status;
-  LONG ErrorCode;
 
   Status = MapDefaultKey (&KeyHandle,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (!RtlDosPathNameToNtPathName_U ((PWSTR)lpFile,
@@ -2903,7 +2769,6 @@ RegSaveKeyW (HKEY hKey,
 				     NULL,
 				     NULL))
     {
-      SetLastError (ERROR_INVALID_PARAMETER);
       return ERROR_INVALID_PARAMETER;
     }
 
@@ -2931,9 +2796,7 @@ RegSaveKeyW (HKEY hKey,
   RtlFreeUnicodeString (&FileName);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtSaveKey (KeyHandle,
@@ -2941,9 +2804,7 @@ RegSaveKeyW (HKEY hKey,
   NtClose (FileHandle);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -2961,12 +2822,10 @@ RegSetKeySecurity (HKEY hKey,
 		   PSECURITY_DESCRIPTOR pSecurityDescriptor)
 {
   HANDLE KeyHandle;
-  LONG ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
     {
-      SetLastError(ERROR_INVALID_HANDLE);
       return ERROR_INVALID_HANDLE;
     }
 
@@ -2974,9 +2833,7 @@ RegSetKeySecurity (HKEY hKey,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   Status = NtSetSecurityObject (KeyHandle,
@@ -2984,9 +2841,7 @@ RegSetKeySecurity (HKEY hKey,
 				pSecurityDescriptor);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -3097,15 +2952,12 @@ RegSetValueExW (HKEY hKey,
   PUNICODE_STRING pValueName;
   HANDLE KeyHandle;
   NTSTATUS Status;
-  LONG ErrorCode;
 
   Status = MapDefaultKey (&KeyHandle,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if (lpValueName != NULL)
@@ -3136,9 +2988,7 @@ RegSetValueExW (HKEY hKey,
 			  (ULONG)cbData);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;
@@ -3211,17 +3061,15 @@ RegSetValueW (HKEY hKey,
   UNICODE_STRING SubKeyString;
   HANDLE KeyHandle;
   HANDLE RealKey;
-  LONG ErrorCode;
   BOOL CloseRealKey;
   NTSTATUS Status;
+  LONG ErrorCode;
 
   Status = MapDefaultKey (&KeyHandle,
 			  hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   if ((lpSubKey) && (wcslen(lpSubKey) != 0))
@@ -3238,9 +3086,7 @@ RegSetValueW (HKEY hKey,
 			  &ObjectAttributes);
       if (!NT_SUCCESS(Status))
 	{
-	  ErrorCode = RtlNtStatusToDosError (Status);
-	  SetLastError (ErrorCode);
-	  return ErrorCode;
+	  return RtlNtStatusToDosError (Status);
 	}
       CloseRealKey = TRUE;
     }
@@ -3301,21 +3147,17 @@ RegUnLoadKeyW (HKEY hKey,
   OBJECT_ATTRIBUTES ObjectAttributes;
   UNICODE_STRING KeyName;
   HANDLE KeyHandle;
-  DWORD ErrorCode;
   NTSTATUS Status;
 
   if (hKey == HKEY_PERFORMANCE_DATA)
     {
-      SetLastError(ERROR_INVALID_HANDLE);
       return ERROR_INVALID_HANDLE;
     }
 
   Status = MapDefaultKey (&KeyHandle, hKey);
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   RtlInitUnicodeString (&KeyName,
@@ -3331,9 +3173,7 @@ RegUnLoadKeyW (HKEY hKey,
 
   if (!NT_SUCCESS(Status))
     {
-      ErrorCode = RtlNtStatusToDosError (Status);
-      SetLastError (ErrorCode);
-      return ErrorCode;
+      return RtlNtStatusToDosError (Status);
     }
 
   return ERROR_SUCCESS;