It seems a recent Windows Security Update (KB928843 MS07-008) may cause an issue where the Realtek HD Audio Control Panel may not start after it is installed. If you are getting the error below:
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.
Download this Patch from Microsoft to correct the problem.
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