RTHDCPL.EXE - Illegal System DLL Relocation Error ▷ Lancelhoff

If you've received an Illegal System DLL Relocation Error and your system is using the Realtek HD Audio Control Panel, you might be scratching your head just as I was. After a bit of research, I found out that this error was most likely caused after installing Microsoft's security update 925902 (MS07-017) and security update 928843 (MS07-008).

The problem is that the Hhctrl.ocx file and the User32.dll file that is included in each of these security updates have conflicting base addresses. The resulting error occurs when the program loads the Hhctrl.ocx file before it loads the User32.dll file.

RTHDCPL.EXE - Illegal System DLL Relocation

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.

Fixing Illegal System DLL Relocation Error

To address this issue, follow these steps:

Download the Microsoft Update:
- The Microsoft Update that resolves this issue is no longer available via the original link. Instead, you can find the fix through the Microsoft Support and Recovery Assistant, which provides tools to diagnose and fix various Windows issues.
Manual Fix via Command Prompt:
- If you're comfortable with using the Command Prompt, you can manually re-register the affected DLL files. Open Command Prompt as an administrator and run the following commands:
```
regsvr32 /u hhctrl.ocx
regsvr32 hhctrl.ocx
```
Check Microsoft Support Resources:
- For more detailed instructions and alternative solutions, visit the Microsoft Support website or the Microsoft Support Forums for community assistance.

By following these steps, you should be able to resolve the Illegal System DLL Relocation Error and restore proper functionality to your system.