All I can suggest is to check your bios settings, make sure your not getting hung up trying to detect an agp card. I had a similar problem when I was trying to run a cyrix CPU with no heatsink, it would overheat just doing the memory check and freeze. Make sure your processor is being cooled. I had a similar problem also when one of my memory chips was not seated all the way down. Just some things to check, hopefully it will be of help.