First Success

Remember that first case we had? Its solved!

Had its hard drive removed from the computer and mounted it in a external usb SATA case. (Luckily the hard drive was detected)
Backed important data up in another computer.
Put the Hard drive back into that computer.
Reformatted it with Windows XP.
Put the backed up files back.
SUCCESS!

Suitable for any computers with corrupted system files and cannot boot into the OS, with HDD not damaged.