External drive no longer accessible

Source

A user will plug in an external hard drive and back off all of their important data to that drive in preparation of a format/reload of windows.
They then reboot the machine and boot from their Windows cd. They begin by deleting the primary partition on the boot drive and then formatting with NTFS. They go through the entire windows load with out incident.
Finally in windows they go to My Computer only to see that the external drive is no longer accessible.
Never leave any drive, except the one you are installing windows too, connected to the machine while you are reloading Windows.
There are 2 different problems here:

1. The drive still has a drive letter but it will throw the error “The drive is not formatted would you like to format it now?”.
2. The drive has no drive letter at all and in Disk Management it will say the drive is unallocated or raw.

There is a couple of ways to fix the problem, the first one is to get Recover IT All Professional and allow the software to find your files. You can then mark them and move them off. The problem with this option is that it requires a lot of transferring of files, and you may miss some. The other way to do it would be to have DTI Data Recovery remote into your computer and repair the problem remotely. With a hex editor I can put the drive back to the way it was before this happened. This is a nice option and limits the down time to the user.

If you are restoring Windows because of a hard drive failure, you may need hard drive recovery.
Don’t use Windows restore CD’s if your hard drive is clicking, or isn’t seen by the BIOS.