Catriona:
I personally work on laptops as well as desktops, and it sounds to me from
the desription you gave that your memory crashed. The symptoms: 'You could
turn the laptop on and there would be no reaction at all. The lights would
light up, but that was it. ' are atypical of memory failure in a laptop. People who just tinker with them usually are not aware of that. Also, the major computer manufacturers such as Dell, Toshiba, Gateway, blah, blah, will reflash the bios after replacing the memory, as a precaution, in case the bios was doing something when the memory actually did crash, causing a corruption in the system. This does not always mean there was, just as a precaution in case there is and they just could not readily see it. A case of better safe than sorry.
As far as Vista is concerned it is possible that during some hardware tests
it simply caused the memory, or whatever hardware that was already failing to
completely crash. In this case, it is actually better it happened while you
were still under warranty... One thing I did learn of Vista, it finds
problems that XP does not, and can fix alot of them, however, in your case
may have caused the final crash. My recommendation is try VISTA out, and if
you do not like it, restore your computer back to it's original state.
Meanwhile, during testing, keep any important files backed up somewhere else
like a thumb drive until you decided for sure. Personally I love Vista, and
I am running on an old Gateway computer Pentium 4, 1 GB memory, with 2 500
pata's and 1 80 sata drive. It flies on my machine. The only problem I had
was with the graphics card, initially, but there was an update to it shortly
thereafter. From what I am hearing, most updates have taken care of many of
the older issues spoken of in earlier posts.
HOPE THIS HELPS...SORRY IF LONG WINDED.