Hmmm, this is bizarre. I thought that I might have the Yaha.k virus so I downloaded a yaha.k repair file from Symantec, booted WinXP into safe mode, and ran the repair file. It didn't find the Yaha.k virus anywhere on my drive, but. . .after the repair file was finished I decided to click on one of my desktop icons in safe mode and low and behold the program loaded normally! I booted WinXP back into normal mode and everything seems to work fine now, programs load when you click on their related desktop icons, etc. Norton anti-virus even works again now (I will probably do a full system scan later on).

I checked the Quarantined Items report in Norton anti-virus to see if it had any info on that virus warning it gave me yesterday. It said the virus name is Backdoor.OptixPro.12, and that it had infected the winampw.exe file that resides in my c:\windows folder. When I tried to repair the infected file it said "Could not repair this item", however Norton anti-virus is still quarantining it.

More information on Backdoor.OptixPro.12 can be foundhere.

I'm wondering if my system was really infected in the first place, as the description of Backdoor.OptixPro.12 at the above URL does not seem to match any of the symptoms that plagued my machine.