I had a problem similar to yours when I upgraded to the socket A platform (700 Mhz T'bird on MSI K7T Pro), system was hanging either during bootup or shortly there after on a regular basis. After running through all the simple solutions (drivers,bios,reseating cards and wires, etc) to no avail, I booted in safe mode went in to control panel and disabled all non-esential hardware (ie everything except hard disk, disk controllers, monitor, key/mouse, and elements under system devices), then rebooted in normal mode successfully. Once you reboot successfully go into Control panel and enable one device, then reboot. Repeat this until you reproduce the system lock up. Once you get the lock up again, then you know the last device you enabled is your problem. Its a laborious process, but it worked for me...turned out my USB expansion card was my problem!! I took it out and this system has run smooth as silk every day since. Good luck!