diff --git a/reactos/dll/win32/kernel32/misc/computername.c b/reactos/dll/win32/kernel32/misc/computername.c
index e5bf86c648d..b07e644ab09 100644
--- a/reactos/dll/win32/kernel32/misc/computername.c
+++ b/reactos/dll/win32/kernel32/misc/computername.c
@@ -92,11 +92,19 @@ GetComputerNameFromRegistry(LPWSTR RegistryKey,
         return FALSE;
     }
 
-    if (*nSize > (KeyInfo->DataLength / sizeof(WCHAR)))
+    if (lpBuffer && *nSize > (KeyInfo->DataLength / sizeof(WCHAR)))
     {
         *nSize = KeyInfo->DataLength / sizeof(WCHAR) - 1;
         lpBuffer[*nSize] = 0;
     }
+    else
+    {
+        RtlFreeHeap(RtlGetProcessHeap(), 0, KeyInfo);
+        ZwClose(KeyHandle);
+        *nSize = ReturnSize;
+        SetLastErrorByStatus(STATUS_BUFFER_OVERFLOW);
+        return FALSE;
+    }
 
     RtlCopyMemory(lpBuffer, KeyInfo->Data, *nSize * sizeof(WCHAR));
 
@@ -254,7 +262,8 @@ GetComputerNameExA(COMPUTER_NAME_FORMAT NameType,
 
     if (!TempBuffer)
     {
-        return ERROR_OUTOFMEMORY;
+        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+        return FALSE;
     }
 
     AnsiString.MaximumLength = (USHORT)*nSize;