a friend brought me his laptop, he thought his hdd died so he got a new one and put it in but the laptop wouldnt POST. i reset bios back to defaults and it boots now, however the xp install just hangs. things i have tried: formatted the drive and installed xp using another laptop and swapped the drives back. (hangs on bootup. can get to f8 menu but it freezes loading safe mode too) once i got it to post correctly tried to format reinstall on the effected laptop and windows install hangs. treid to boot to an ubuntu live cd (fiesty fawn) hangs as soon as it says "kernel alive". its not the hard drive obviously, but i dont know what could cause this. i have memtest86 running now, only other option is a new cpu but i dont wanna go that route. anyone have any suggestions?

I would suggest the o/s is hitting a faulty piece of hardware such as a nic or modem or video card or a memory module. .

Yep I agree with per. WinSimple Software

As per said, it'd most likely be faulty hardware. However, it might also be a heat issue. When it hangs (on boot), reboot and enter the BIOS. Check the current temperatures and if they seem excessively high, (after shutting down) check for built-up dust and grime on all the fans and vents. You may even need to re-seat (which means new heat transfer paste/pad) the heatsink/fan on the CPU. If the temperatures look normal, you'll probably have to troubleshoot each hardware component individually. Please let us know if you found someone's advice to be helpful.

Is it a Dell laptop? If so, they have a "bios lock" which prevents loading an O/S from media that doesn't contain an "oembios.sig" (if I recall the name correctly). It's a good day when you learn something