Is there a way to repair this? I do not know when this started and cannot use system restore for the same reason.

Hi KevinArruda,This issue occurs either because of a missing or corrupted Rundll32.exe file or by virus.Let’s follow these methods & check if it helps.Method 1If you have Windows XP installation disc, you may follow this link & check if the issue persists.Cannot find the Rundll32.exe file when you open Control PanelMethod 2You may also run System File Checker [SFC] scan on the computer which will replace the missing or corrupt files & check if the issue persists.a. Type ‘cmd’ in start search box. Right click on cmd in the Program list and then select the option Run as administrator.b. Type the following command, and then press ENTER: sfc /scannowDescription of Windows XP and Windows Server 2003 System File Checker (Sfc.exe)Hope the information helps. Please post back and let us know.RegardsDebleena SMicrosoft Answers Support EngineerVisit our Microsoft Answers Feedback Forum and let us know what you think.