I crashed the master boot record on an external USB Hard Drive (It fell and unpluged in the middle of an access). It's not just the FAT that has been damaged but the MBR too.
Do you know a free software that would permit to rebuild that MBR and the corresponding FAT ??
Use the following command, you should have this as part of your windows installation :
Re-writes the hard disk drive's Master Boot Record. Useful if you hard disk drive just won't boot up properly after you format it or after you suffered from a MBR-corrupting virus.
Requires DOS 5.0 or higher.
I hope this helps you.
I had read about this possibility but I did not try it because I did not see any option and I would like to be sure it is not going to rewrite the MBR of my computer HDD !! Have you already tried it ? Do you know for sure if we can choose on which hardware the command will apply ?
Personally, I would take the drive out of the external enclosure and install it as the only drive on a computer in order to fix problems like that.
That still would not fix his problem, because the partition data has been corrupted. It would allow him to use the drive, but it would mean he would lose all the data on the drive. Unfortunately, I am worthless about data recovery (no experience in the field), so all I can reccommend is google-ing it, although I am sure you have tried to do so already.
The only suggestion I have is to try and get hold of a Linux live cd, boot up and see if you can access the drive to make a copy of the data you want to use.
After that you can try the fdisk /mbr without fear of losing data.