computer shuts down while on the internet?

Friend called with ther computer shutting down while on the internet.

I remember a virus that did that, qhost ot welch (I think, something like
that). Not sure if it was one of them, there was a simple virus removal tool
for it from symantec, but can't remember which virus it was?
thanks
also posting to win98 newsgoup, not sure what systme they have till I go
voer