Fix rthdcpl.exe – Illegal System DLL Relocation Error

You may receive the following error message soon after you have updated your Windows XP PC with Service Pack 2:

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 error message is displayed when a recent Windows XP update causes some problems with the Realtek HD Audio Control Panel versions1.41, 1.45, 1.49, and 1.57.

Note: You may also encounter this problem if you have ElsterFormular versions 2006 and 2007, TUGZip version 3.4, CD-Tag version 2.27, Suunto Ski Manager versions 1.0.2, 1.1 and 1.2, and BMC PATROL version 7.1 programs on your PC.

Cause of the Error

This problem usually appears after the security updates 925902 (MS07-017) and 928843 (MS07-008) are installed on a Windows XP Service Pack 2 computer. The problem occurs with the program listed above due to conflicting base addresses of the Hhctrl.ocx file included in the security update 928843 and the User32.dll file in security update 925902. The error message is displayed when a program loads the Hhctrl.ocx file before the User32.dll file.

Resolution Method

You may follow the methods listed below to resolve this error message. After each method check if the error is resolved.

Update the Program that is Generating the Error Message

First, try to look for an update for the program that is generating the errors. For example, if the error message indicates a problem with Rthdcpl.exe, try to search for and update the Realtek drivers.

You may try to update to Realtek HD Audio Control Panel 1.64 that does not display this error.

Install Windows Updates

  1. Visit the Microsoft Update Web site, and then install all essential updates on your Windows XP Service Pack 2 computer.
  2. Check if the error is resolved after the updates are installed. If the error still remains, do the following:
    1. Open the Update for Windows XP (KB935448) webpage.
    2. Click the Download button-if this button is not available, you may have to first click the Validate button to ensure that your Windows XP Service Pack 2 is genuine and then proceed with the download.
    3. Next, click Run.
    4. Follow the instructions given on the screen to install the update to your PC.

To prevent errors, such as the “Rthdcpl.exe – Illegal System DLL Relocation” error, it is essential that you keep both Windows and the programs and device drivers installed on your computer updated. On your Windows XP computer, you can turn on the Automatic Updates feature to ensure that all your Microsoft-related products are updated on a regular basis. Also, if the automatic update feature is available with other programs and device drivers, you should enable it to keep these programs updated.

It is also recommended that you use a good Windows registry tool, such as RegServe, to regularly scan and clean your registry. This will not only help you optimize the performance of your PC, but also help you prevent several unwanted computer errors and problems from occurring.