I would suggest you do an online virus scan of your system (it's free) just to make sure you didn't get hit with a virus on the W98 system prior to networking it to XP. There are some viruses that actually disable your antivirus program and you have a false sense of security thinking your program is working properly when it isn't. An on-line scan will find anything that may be suspicious and for most viruses there are tools you can download that will remove stuff your antivirus program can't for some reason.
You can get an online scan for viruses, trojans and variants at:
I recently networked a laptop using XP Home to a 98se machine. While re-organizing files, I gradually noticed quite a few files on the 98 machine as seen through XP were showing a Date Created attribute as "9/11/2001 11:45PM". Give or take a few minutes. Hundreds of them. The 98 does not show this attribute. Most often, the "create" date was newer than the "modified" date. I did a cursory search, but thought I'd ask the brain trust at CNET if anyone has heard of a virus that might do such a thing? For what it's worth, I do scan both machines with AV software weekly. If not, any other thoughts?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic