Windows: Scanning for Viruses in Safe Mode

Scanning for viruses and spyware when Windows is running normally can often successfully eliminate them, but in some instances it is necessary to activate Safe Mode before scanning for them. Some viruses automatically load as system processes when Windows is started normally, making it impossible to delete them. There are also viruses which can make it difficult to access and use anti-virus software; running Windows in Safe Mode may temporarily disable such viruses while they are deleted.

If possible, update the virus detection data of your anti-virus or anti-spyware software before entering Safe Mode and scanning for viruses. Although there is a "Safe Mode with Networking" option, I was unable to connect to the internet for updates while using it. This may depend upon your type of internet connection and internet service provider.

To start Windows in Safe Mode, restart or turn on the computer and press the F8 key right before Windows opens. Then select Safe Mode from the menu (using the arrow keys), press ENTER, and select the appropriate operating system from the next menu if it asks for this. After this, Windows will boot up, using a basic configuration (it will look somewhat different).

Then you can go ahead and start scanning for viruses. I tested AVG Free Edition, Spybot Search & Destroy 1.3, Ad-Aware SE Personal, and HijackThis 1.99.1, and didn't have any problems scanning for spyware or viruses with them in Safe Mode. There may not be any screensaver activated in Safe Mode, so you might want to turn off the monitor if the computer is to be left scanning for a long period of time.

If the virus is preventing all internet access (either directly or by preventing access to Windows when not in Safe Mode), you may be able to download an update from the anti-virus software provider's website on another computer and copy it to the virus-affected computer using a floppy disk, recordable compact disc, pen drive, Zip disk, or other removable media.

If scanning for viruses takes a long period of time on your computer, optimizing this might be a good idea; spending a lot of time on virus scans puts wear on the hard drive and uses more electricity. Deleting unnecessary programs, eliminating data which is no longer needed, and clearing temporary internet files before scanning will reduce the amount of files the software has to scan for viruses, thus speeding up the process.