Safe Mode Guide
Sometimes it’s a good idea to run things like virus and spyware scans in safe mode.
To boot your machine into safe mode, see Microsoft’s articles depending on your Windows version:
Once you’re in safe mode, the screen may look odd (very low resolution, colours not showing properly etc.), but you should be able to run a virus or spyware scan. With Windows 2000 and XP, you can run in “safe mode with networking” which will allow you to update virus definitions, but with 95/98/Me, you will need to update these before booting in safe mode if possible.
To exit safe mode, just reboot the machine normally.