Rthdcpl.exe – Illegal System DLL Relocation

This has been all over the newsgroups but since this is something i came across today i’ll just post about (also in case I need to remember!)

Had a customer who called to say he’d done a windows update and after rebooted got the following 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.

The problem is to do with an updated version of Hhctrl.ocx (from update 928843 )having the same base address as an updated version of user32.dll (from update 925902)

This problem occurs when you have Realtek HD Audio Control Panel installed. 

The knowledge base article is 935448 and you can download the hotfix directly from here

I installed the hotfix, rebooted the PC and problem solved