When I installed an upgrade to Norton Systemworks on a notebook running Win98, Norton deleted a number of DLL files used for my WiFi.  I was able to download and install the files from:

http://www.dll-downloads.com/files.asp?filetype=dll&os=Win98se

My buddy Paul runs CastleCops that has forums dedicated to computer security and fixing what is broke.

Thanks for the MS beta spyware info.
I found this interesting, but they left out windows 98!
http://www.avantgarde.com/xxxxttln.pdf

'The experiment tested to see how well commonly used computer platforms withstand Internet attacks in the wild.
The experiment quantifies the amount of time it takes for a computer to be attacked and compromised when placed on a live network for the very first time and qualifies the type of attack method used to successfully compromise a computer over a two week period.'

I heard that since this was done, that more Linux and OS X vulnerabilities have been exploited to show they're not invincible.