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 DLLC:\WINDOWS\system32\JJCTRL.OCX occupied an address range reserved for Windows system DLLs. The vendor supplying the DLL should be contacted for a new DLL.
Caused by Microsoft Security Update KB925902 or KB928843. The update to correct the issue can be found here.
The full article where I found this can be found here: