What is rundll32.exe??
 

I just checked up on prime95 and found that its timings were REALLY slow. So I brought up task manager to try to find out what was stealing all my CPU cycles.

It showed up that rundll32.exe was using up 50% of my CPU. Now seeing as though I have a P4 with hyperthreading, that means that it was effectively using all of my CPU power.

I was just wondering what rundll32.exe was?? What does it do?? What would have caused it to be started??

Rundll32.exe is a program that runs routines in 32-bit-dlls. There's also a 16-bit-variant, Rundll.exe. It is quite possible, that there is an entry in the startup folder or the registry. E.g. RunDLL deskcp16.dll,QUICKRES_RUNDLLENTRY or Rundll32.exe powrprof.dll,LoadCurrentPwrScheme.

HTH

Benjamin