I was recently given a desktop from my brother as a gift. He decided to upgrade and left me his Dell XPS studio. The only thing he took out of his machine was his hard drive, so I went out to staples and purchased the Seagate Barracuda 500 GB SATA / 16MB CACHE / 7200 RPM. I physically installed the hard drive in the machine and plugged everything in correctly. I started the desktop up, put the Seagate disk in my DVD/CD drive, hit F12, and booted from the disk. The only thing the occurred was a flashing underscore in the top left hand of the screen. I said fair enough. I unplugged the driver from my computer, formatted and installed the OS (Windows 7 pro 64 bit). I reinstalled the hard drive in my computer, booted up, hit F12, booted from my hard drive, and still I am getting this flashing underscore. No matter how I try to boot I can't figure this out. Any help would be appreciated. Thank you for your time.