I have been trying for countless hours to figure out why my vista os will not boot up. It downloads from 25%-75% of the files and then automatically shuts down the computer. I have tried using one ram stick (2gb) instead of 4gb. I tried the ram stick in different slots.. still nothing worked. I did use the floppy disk to get the hard drive drivers. Please help me, I have tried everything!!! My motherboard is Asrock 4core1600twins-p35. My memory = ddr2 2 x2 2gb 1066. The manual did say something about fixing the jumpers if you had a combination of a 1333mhz fsb for your cpu and 1066 memory. Could this be what is holding me back? I really doubt it because the ram still functions, just at 667mhz instead of 1066. My BIOS settings are at exactly what the manual says to use, but it still won't work. This is sooo annoying! Please someone help me .