Only intel cpu's slow them selves down if they over heat, not amd's.
Do the obvious things like defrag your hard-drive then get
ftp://ftp.pcworld.co.nz/pcworld/file...tupcpl_exe.zip that file.
Open and run it to see what rubbish is loading on startup and delete all the crap (if u dont know what half of it is then post it here and I'll tell u what u can safelly remove)
How long since your last format? when I ran w98 I had to format every month or two as w98 would crap out real bad after that amount of time.
Also get
http://www.outertech.com/download.ph...5169ecd20ca654 cachman as that helps a lot on w98