What's happening? - Windows starts up, then everything goes dead

[ErikP]

Any help in investigating & resolving the following appreciated ... not sure what's going on ...

just started today, everything was alright before, and nothing (knowingly) changed ...

on a machine with Win XP Pro SP1, it boots OK with normal boot messages flying past, then Win starts and it looks OK, mouse works, but as soon as the Win XP start up screen with the moving blue dots finishes, everything goes dead

it looks like the connection between the machine and the keyboard/mouse & monitor stop working because there is just a black screen and no response to keyboard & mouse - also the neon on the monitor goes off

I tried another monitor, keyboard & mouse but same problem.

what's happening? how do I investigate when I can't see anything?

is it a virus (the machine has got an up to date copy of Norton AV)? motherboard failure? power issue?

 

[IronDuke]

Try safe mode or last known good. Should have installed SP2 by now.

 

[Rick]

It could be a variety of things, but it is almost certainly a problem with your Windows installation. The question is how did the problem appear? Was it from hardware failure? Was it a virus? Did Windows finally execute itself? etc..

Providing it is not hardware failure, the following may be a solution. However, it should only be considered when there are no other better ideas:
https://www.techspot.com/vb/topic8356.html

You may want to try safe mode and last known good configuration as above. Sometimes LKGC works (but not often). Safe mode might get it to boot so we can help you fix your problem without having to try a modestly risky Windows repair.