If the virus you've been infected with is old and well-known, there will very likely be a "removal kit" on the Symantec Security Response website which you can download, install, run, and be done. If this is true, if you're lucky, you'll save yourself a lot of time and trouble.

If you don't have the necessary software (Operating System disks, software disks, device drivers), and have no way of getting them, then attempting to repair the system is the only option you have. It's very important to keep the system installation and repair disks that come with your computer. If you didn't receive such disks, then your repair options are much more limited.

OIT no longer offers no-cost virus removal services. The closest thing to this is University Computer Services, which does offer a competitively priced operating system reinstallation service.

If the virus or worm is based on the latest technology, it probably didn't come in alone. It likely contains one or more trojan horse programs to replace programs you trust, and the ability to fake the results of virus scans, task manager results, and other programs commonly used during a virus cleanup.

Removing these programs effectively wipes out all evidence of the intruder's actions on your system. If you wish to investigate and prosecute, you may not be able to.

Though you may find and remove one (or two, or three . . . ) infected files from the system, you might not get all the viruses or worms, and end up infecting your friends and neighbors when you attempt to rejoin the network.

If you do remove all the actual viruses or worms, your operating system could still have been riddled with back doors, designed to grant the intruder easy access to the system in the future.

If you attempt to regain control of your system and fail, you might be forced to perform the clean system reinstallation you tried to avoid in the first place. Avoiding the solution could drag out the problem over weeks or even months.

There is literally no way to be absolutely certain your machine isn't still infected. This can be nerve-wracking.

100% confidence that you've removed all infections from your computer.

Can take considerably less time, if you prepare for it. People who choose this route are often up and running within a day of getting infected.

You can almost always find the necessary device drivers at no cost online.

Painless procedure, relative to hunting down an IRC bot (which might not be possible!)

If you do it yourself, it costs nothing more than your time.

You can often get free help from your friends, neighbors, or family.

If neither of these options are viable, University Computer Services offers a secure operating system reinstallation service.

Freshly installed Operating Systems run faster than ones that have been compromised by viruses and especially spyware.

If you forget to burn your personal files (papers, music, saved games, etc.) to a CD or other storage device, you will lose them permanently.

Might cost you money if you can't perform the reinstallation yourself.

You might not have all the necessary software or device drivers.

You might not be able your files to a CD, in which case you would need to transfer your files to a USB memory device or to your personal 1GB storage space on the University's servers.

You might have a large number of programs or a lot of music to back up.