rundll32.exe – Entry Point Not Found`

I have WinXPPro. I tried to remove all instances of Norton Antivirus 2003, due to problems, and incurred the following error: The procedure entry point RemoteAssistancePrepareSystemRestore could not be located in the dynamic link library WINSTA.dll. I tried to repair this via the WinXPPro CD, but to no avail. My System Restore ability is gone. Can anyone help?