red light means HDD is running this means that at least "mechanically" the drive is working.
Windows is trying to find the boot record on the drive, and failing.
Testdisc click here
Drive Rescue click here
may help you recover the boot record nd / or any files on the drive.
If you cannot recover the boot record but can recover files, once you have rsecued the files then try Disk mangement and reformat the drive to make it usable again.