I think the test is in the doing.
If there is anything one can do to make W98SE reasonably stable, you've really done something. In my case, there is a very short list of programs installed on the IBM, and very little in the way of files, it should have been relatively tame.
However, it always had this tendency to crash if left unattended or have something huge and terrifying running in the background that more or less was about as bad as a full on crash.
I thought perhaps it had something to do with my bargain basement hardware upgrades or my BIOS update-although I WAS smart enough to get the new processor in a sealed box, everything else was salvaged or dirt cheap.
I had pretty much narrowed it down to something to do with Norton as it worked a lot better when I manually closed some items that were associated with Norton. The only two other potential sources of trouble were Nero which came with my CD
/RW drive and the Linksys monitoring stuff-both of which required a bit of tinkering to get them to live happily in the same house.
In any event, everything seems to be working nicely.