Uh Oh You've found a virus

Uh Oh. You've found a virus. Now what do you do?

Do's

The first thing to do is call your computer person if you have one. Viruses can be very tricky to remove and if you don't follow proper procedure you can very easily lose data. Also, if you are not familiar with DOS or working with manual commands you can get lost quickly. A lot of viruses still require some manual removal from a DOS prompt.
If you are brave you can try cleaning the virus yourself.
The best thing to do if you are cleaning yourself is to find out as much as you can about the particular virus you are infected with. You don't win a battle without proper intelligence. Most antivirus companies have a virus encyclopedia or virus information section of their website explaining just about every virus in existence. Check out my links to virus information libraries.
Print a hard copy of the virus information. If you lose access to your computer for any reason you have the information to manually removed certain aspects of the virus manually in DOS.
Be sure to have you original windows CD and/or disks handy. A lot a viruses attack certain windows system files. If these files cannot be cleaned you will need to reload them from your original disks.
When you find the information, follow it to the letter.
See if your antivirus manufacturer has a downloadable cleaning utility for that particular virus. This can save you a lot of time and may eliminate the need to go to the dreaded dos or command prompt.
Always get the latest virus definition files from your antivirus manufacturer. They are always updating them and a virus that couldn't be cleaned a few weeks ago may have a cleaning option now.
Once you think you have everything cleaned up make one last final scan of the system. Make sure your program is set to check all files (not just program files) and you have the very latest definition files available.

Don'ts

Do not format or repartition your hard drive. This should be done as a last resort and unless the virus has destroyed all of the information on the drive it should not be necessary. NOTE: Some viruses relocate or hide the FAT or file allocation table somewhere else on the drive. A skilled computer technician should have the ability to recover this kind of damage.
Do not send email to anyone else warning them that you had a virus until you are absolutely sure you have cleaned all of it. This will prevent spreading the virus to others. The key to this is making sure you do a full scan of all files with the latest virus definitions.
If you are part of a large business or corporation do not attempt to clean the virus yourself. Not only can you affect more users than yourself but you may destroy evidence of how the virus was able to penetrate your company's security. Call your company's internal technical department ASAP.

Disclaimer:

These set of guidelines are here to prevent you from having a bad experience. Viruses are unpredictable and ever changing. Even following these guidelines you can still have a bad experience and data loss. I am not responsible for damage that is inflicted on your PC by trying to clean it yourself or following any of these guidelines. When or if you get infected, think clearly, act responsibly, and when in doubt, call a professional. Happy Hunting.

Updated 05/22/2005