I installed Windows 2000 on a hard drive, upgrading it from Windows NT. I installed it on a 200 mhz's CPU. The problem I am having is that I am trying to take the hard drive out and put it in a 66 mhz's CPU. The hard drive has Windows 2000 and DOS on it. When I put it in the older CPU, it said it was "Missing Operating System". I booted the PC up with a boot disk and was able to read the C drive. When I took the hard drive out of the older PC and put it back in the 200 mhz's CPU, it booted up fine. I believe I have cables right being that I can read the C drive when booting up with a boot disk. I reason I installed it on 200 mhz's CPU is to install the software faster. When I do a fdisk on the older CPU it does give me a different drive partition setting.