I have one SATA hard drive that is loaded with XP and runs great as the only hard drive installed. I also have a SATA hard drive that has Windows 7 installed and when I remove the hard drive with XP and physically swap to the hard drive with Windows 7 that also runs great. My questions is this: both hard drives are setting on my desk and each drive has a different OS system installed. I am tired of physically swapping hard drives to access the different OS. I can attach both SATA drives to my motherboard but not sure what I do next. No doubt there is something I am going to have to do in the BIOS to get these hard drives to load on demand. I want to select which OS (hardrive) I will use on that boot up. Is there a simple explanation on how to do this? Both OS programs are already loaded on it's own hard drive and both work individually. What is my next step or is this possible? Appreciate any help I can get.