Sometimes a piece of software will hose the boot.ini file and misdirect Windows but everytime I've ever seen this error come up it's due to drive corruption/death. It may NOT be the hard drive. Motherboard instability would cause this as well. Best bet would be to yank the hard drive, connect it to another computer that's known working and get the data off. If the drive is failing, everything you do is further diminishing the chance you'll successfully be able to read your data.