System specs
AMD Athlon 64 Processor 3000+
WinFast PX6200 TC GeForce 6200 TurboCache 128 MB
512 MB RAM
300 W PSU
Windows XP service pack 2.
To answer the hdd question previous, the hdd lights comes on but as soon as the pc has frozen/locked up its goes off.
As for something I am doing and the lock up, the lock up happens whatever I do or don't do. If i just turn my PC on, xp loads and the login screen appears, If i leave it it will lock up, If i or any other user logs in the lock up happens also. So it seems completely irrelevant of what is being done as the lock up happens within about 30 seconds - 1 minute everytime.
It could be getting too hot but, looking at this logically, I don't see it being the answer as the lock ups happened, after a system restore the pc ran for around 7 hours under varying load. Then the lock up's happened again, and happen after the same time. Also I have had it running in safe mode for a few hours with no problem either. I will have a look though for dust and clean the heatsink if dusty.