Okay, I've just put a new hard drive in my computer and re-installed Windows XP. The PC was a Medion shop-bought one (about 2 years old) complete with software, so Windows is specific to this machine. I had no problems with installation and it worked fine a couple of times since then, until yesterday. I turned the computer on and it started the POST, then hung on the BIOS startup screen (just as the "Press F1 to enter Setup" appeared). When this happened I couldn't even reboot it, the power button had no effect... I had to turn off the power button on the PSU. After waiting a while I tried again and it worked fine! This has been happening at random intervals since. There are no other problems - once it boots, everything is fine. Any ideas what is causing this? Spec: Pentium 2.6GHz processor, 512 RAM, Windows XP, DVD ROM, DVD RW, Radeon 9600TX graphics, 250GB Sony HDD, 250W Fortron/Source PSU (Basically just as it was in the shop, except for the hard drive) Oh, one other thing: there was a thunderstorm yesterday... the computer may have been switched on at the time (I wasn't here) but there was no power cut. Not sure if there was a power surge, though :-( Please help!

Might want to get another PSU and also a surge protector. Thunderstorms are bad with computers so I wouldn't be surprised. When a thunderstorm comes, I usually just unplug my computer from the outlet just to be on the safe side. Jim R

Also try to troubleshoot, just take everything out, except one thing of ram, the video card and the harddrive. Also you might want to run a mem test to see if you have faulty ram or harddrive. Jim R

Thanks for the replies :-) I've checked all the connections inside and run mem test and disk check; everything is fine there. I guess it's likely that it's the PSU, then... I'll have to get a new one. And a UPS. And a surge protector :-(