Basically I'm working on a friend's XP laptop, because it had some serious issues with viruses/malware which ended up cutting off the admin access to regedit, task manager etc, and safe mode did not work.

So in the end i decided to back up the files and do a format and fresh install of XP SP3. After installing the first part of XP and then rebooting it to finalize the installation, it would briefly pop up with an error message, then commence an endless boot loop of the same thing over and over. I tried various things but then decided to use a utility disc, UBCD, to format the hard drive again and then try installing XP again.

Well i'd just finished formatting, exited and shutdown, to find now that it won't boot at all. or I'll get the logo (Sony VAIO) and it'll just shutdown again.
The power lights will come on but no screen image.

So basically, I'm lost at what to do with this 'the lights are on but nobody's home' problem.

Please, any help is better than none.