It was my friends Seagate 500gb ST3500418AS hard disk and he has installed vista in it.I asked his hard disk to copy some data.I used his hard disk as my second boot device and my 250gb as the 1st boot device.I connected them both and started the pc.At irst it was detected by the BIOS and i continued then it was loading for more than 10min then i put his 500gb as the 1st boot device and booted it.But it showed the error message Please insert boot media and press continue what shall i do