My Gateway 2000 G5-200 computer originally came with the 0AAES045.ROM bios. I decided one day to upgrade the computer from W95 to W2K. It worked great until I flashed the bios with the latest from Gateway (0AAES054.ROM). That ROM will kill the CPU's ability to boot anything over W98. Use the 045.ROM and you will be able to boot the NT Based OS's. I am currently running XP w/160MB RAM. Sweet on a 200MMX.