There's not a lot to go on but there may be a clue in that truncated file. This implies that part of the system may have become corrupt. Have you tried using one of your restore points? I'm fairly new to XP so can't be sure how well these work, but from the tales I have heard, if you can go back far enough to before the problem first occurred, you can clear most problems. If that doesn't work, try a repair from your install CD.
What information would you need. The computer is getting worse. The cut outs can happen at anytime, which is making it unusable. All the fans work and the computer's temperature is about 10 degrees celcius below the warning level.
check these things make sure the fan and heatsink are located properly and that the fan is turning(dont always go by the temperture probe) Make sure you video ard is located properly Start ure system in safe mode and use that for a while. If it works fine, then you will know if a file is damaged. If that is the case, then turn off the pc .turn it on again but this time put in your xp disk and choose the option to repair your current version of windows
If your pc doesnt work in safe mode, then it is highly likely that ure psu is knackered.
Windows XP seems to work fine now. The fan seems to be working. The bit I don't understand is that the monitor is still powered and the motherboard LED light are still lit before, during and after the cut out. I will be investigating PSU's. I had another PC with PSU problems but it just died. I couldn't get the machine to start like I can with this one.
Seeing as the solution could be a new Power Supply Unit. Would a 300/350W power supply be big enough to support a P3 450MHz processor, 2 CD/DVD drives, 1 Hard Disk, 1 Floppy disk drive and 3 expansion cards (Modem, sound and Graphics). I have no idea what the strength of my current one is.