This is an interesting issue. I would recommend trying the following:
1. Boot in to Safe Mode and see if this still happens. If you're unsure as to how to boot into Safe Mode, Google it.
2. Go to Start->All Programs->Accessories-> Command Prompt. Type in the command "sfc /scannow" (without quotes) and hit enter. This will scan your Windows installation to make sure all the Windows files are neither corrupted nor missing.
3. You should run a virus scan. If you can't update your virus scanner, then download the Kaspersky Rescue CD image file and burn it to a CD. Boot your computer from that CD and scan for viruses. It will remove any infections it finds.
I hope at least some of this helps!