Every PC user tries to avoid computer viruses, but infections can happen in a matter of seconds. If you've accidentally clicked on an unrecognized email attachment or visited a few disreputable websites, you might pick up a virus or Trojan horse, at which point you'll need to disinfect your PC to continue using it safely.

The trouble is that many viruses try to prevent you from running antivirus software directly from your Windows operating system. To get rid of them, you need a dedicated tool like AVG Rescue USB.

As the name of this antivirus program implies, it's a simple but powerful antivirus tool that you load onto a USB drive to treat an infected PC. By plugging your USB stick into an infected computer and restart it, you'll run the antivirus program before booting Windows to rid your PC of malicious software. Depending on your computer, you may need to go into your BIOS and select your USB stick as your boot device, so if you're not familiar with this process, this might be a tough program to use. However, it's a powerful tool that provides necessary assistance for PC users with netbooks and other computers that don't have CD/DVD drives.

AVG's antivirus tool doesn't have a pretty interface, but it handles virus scans effectively thanks to up-to-date definitions and a comprehensive approach. It's a fairly slow program, but its capable antivirus and file repair tools make it worth the wait. You also get a file manager, a hard drive recovery tool, a network resource application and a registry editor, so if you're fairly adept at troubleshooting, you'll find a lot of great features to appreciate here.

Overall, AVG Rescue USB is a great little utility with a slime 84 megabyte file size. It's well worth a try in an emergency.