Please note - IMPORTANT:Don't delete the worm file 'sirc32.exe' before you run the program at the first link I posted.

You will screw up your system.

According to the F-Secure site, what appears to happen is:
1. The worm copies itself to c:\recycled\SirC32.exe
2. It CHANGES Windows so windows thinks it has to run this file every time you try to run a program.
3. If Windows can't find SirC32.exe, it doesn't 'think' any exe file (program) can run.
It sounds like if you simply delete the worm, none of your programs will run.

The downloadable file at F-Secure should restore settings on your computer so Windows quits looking for the worm. After that, you can delete it.