The problem with Win98 is that is is not quick (especially while using Internet Explorer 6 and anti-virus software). It also has security issues, can easily be damaged by spyware or viruses and will no longer be supported by Microsoft soon.
I'm already the guy who peole call when their computer isn't working. I could always make an image of a Win98 drive as soon as it is up and running as a back up. Still I was looking around to see if there was an OS that would run fast (like if you were to install Windows 3.1 on a 266 MHz it would fly).
Slax might be a solution if there is a way to speed up the boot time.