Searching around, rundll32 is required to load DLL files that
are required by programs.
Your program might be corrupted, so a reinstall might help.
It is also used to load some video cards. Nvidia is one fine
example. If you have a Nvidia card, try uninstalling the drivers
and reinstall it.
Several Microsoft experts have also pointed out that it's related
to spyware, so I guess if you could post up a HijackThis log, it
would help a lot.
http://www.mcse.ms/message914511.html
