i know this subject it drawn to death but all the solutions i have come by doesnt seem to work for me. here is my specs first off... athlon 64x2 4200+ 4gb of pny optima ddr3200 400 2 sli'ed 8500gt 512mb vid cards 250 gb sata hd vista home premium 64 bit edition asus a8n deluxe sli Now my problem is I am trying to get 4gb of ram to get read by windows. Now i know 64 bit can read 4 gigs so i know thats not the problem. My mobo can support up to 4 gigs and it is read in the bios as 4 gigs. I enabled sw and hw remapping and my comp restarts before it can get to the windows loading screen. i disable hw remapping and enable sw remapping and i get to vista but only 3 gigs are read. Any suggestions?