Re: Invalid system disk, relpace the disk and then press any key
If SMART is enabled, get a copy of ubuntu 10.04 and boot into the cd. Then on the Live OS, go to on the of the screen, "System", "Preferences", "Disk Utility".
Then a program should open up and click on your HDD or the left. Then click on the button that says "Check Smart Status." This will tell if you have any bad sectors. I usually run the short HDD test and it is pretty accurate.