As I was resurrecting an old Win98 machine, I quickly became aware that some of the stuff we use with XP does not work with Win98 unless we have special drivers. The USB memory stick is one thing that does not work without special drivers.

Also, there is some software that will not install on a Win98 system. Like Firefox 3 for instance. Firefox does not appear to have made any provisions for obtaining earlier versions of their browser. As near as I can tell version 2.0 is the last version that does not require at least Win2000.