Rthdcpl.exe - Illegal System DLL Relocation
When you start a computer that is running Microsoft Windows XP with Service Pack 2, the Realtek HD Audio Control Panel may not start. Additionally, you may receive the following error message:
Rthdcpl.exe - Illegal System DLL Relocation
The system DLL user32.dll was relocated in memory. The application will not run properly. The relocation occurred because the DLL C:\Windows\System32\Hhctrl.ocx occupied an address range reserved for Windows system DLLs. The vendor supplying the DLL should be contacted for a new DLL.
This occurs because of a downloaded security update from Microsoft, they released a fix for the problem on April 3rd 2007 - you can read more about this and download the 935448 package to fix this at: