As I said before. That rundll.exe is MALWARE, you don’t want that back.

How to disable system restore.

Get a Windows XP cd and run the sfc is I suggested, place all original Windows files it asks for back from the cd.

Also check this key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
If you see c:\windows\system\rundll.exe there, remove it.