|Unplug the computer. unplug the hard drive cables from either the drive or the mainboard. Unplug printers or other USB devices, except for the keyboard if it is USB.|
Plug the power cord back in. Power on. The display should come on with a boot error. Go into the BIOS and test memory. If that passes, power down (unplug power). re-attach the hard drive. If it boots, have windows run check disk.