I am the man.
We had this computer today that wasn't loading Windows entirely. In fact, if you checked the Close Program dialog, there was nothing displayed. No running programs. Bad stuff.
Booting into safe mode caused Explorer to crash like mad.
So we went to DOS. Hooray for Win98 that still lets you do that. I started checking directories and such, went through the system folder looking for recently modified files. There turned out to be a few from today, so I looked at those. None of them seemed familiar, but they looked like randomly generated file names. From experience, working with a Hybris-infected machine last week, I had found that that virus drops trojans as its way to check ports - with randomly generated file names. So we replaced the Winsock dll file and booted up again, and voila! Windows started properly.
It turned out that there were over 1,000 of these random files in quarantine - the user said she kept getting notifications and it was bugging her. *growls* So we deleted all those and everyone lived happily ever after.
I love virii.