Black screen of death - help!

[stillfrazzled]

Compaq laptop (approx 2yo) has been running v slow at startup for a couple of weeks - I'd blamed Virgin PC Guard.

Closed it down earlier and appeared to be OK, started up again just now and can't get desktop or Vista. It runs checks etc, then...nothing. Just a black screen. Can only get online through going to Help, and then Microsoft downloads.

Please, please, anything I can do?

are there any messages or just a black screen? does it say 'unable to find anything' when it goes through the messages?

when it goes through checks I mean

I thought the screen of death was the dreaded blue one???