Very strange situation. I built a new system with new hard drive which turned out to be faulty so I installed Windows 7 on my old 500Gb hard drive. A couple days later I bought a new WD 1TB SATA drive and installed it into my case. I installed Windows 7 on it but forgot to unplug my old hard drive. Now both drives have to be plugged in in order to boot. If I unplug the old hd it get error message "Reboot and select proper boot device or insert boot media in selected Boot device and press a key" when I boot from the new hd. Bios is set properly with the WD 1TB drive as first boot drive and dvd as second and is set as AHCI. What could be the problem? I want the old hd out of the case. Also, upon boot a black screen with white text asks me to select the OS I want to boot and gives 2 options, Windows 7 or Windows 7. One is linked to old drive and 1 to new drive.