I'm a believer in Norton Systemworks. You can buy a new version for $69 or a 2002 version from Amazon.com for $19, and then upgrade it to the 2004 version later. It gives you tools that will fix problems for you as well as anti-virus. I found it to be cheap insurance ...

http://www.symantec.com/sabu/sysworks/basic/

The 2004 version will be out in a few weeks.