I bought a new Western Digital Black 640gb and installed windows 7 on it and everything, so both of my hard drives loaded windows 7. I decided to format my old hard-drive(750gb) and keep my 640gb hard-drive as my one primary hard-drive and my other hard-drive as just storage. Once I formatted my 750 gb hard drive, I'm unable to load windows with my 640 GB hard-drive ! What the hell did I do?! Under Disk Management, 640gb: Disk 0: Healthy (System, Active, Primary Partition) 750gb: Disk 1: Healthy (Boot, Page File, Crash Dump, Primary Partition) Did I install WIN7 wrong or something? What can I do, to make my DISK 0 my hard-drive to actually boot up and work like normal. I had to reinstall windows 7 on my 750 gb hard-drive just so I can come online and ask for help . If someone knows how I can make my 640 gb hard-drive work again, please help Thanks!