I have a external hard drive, which I think got corrupted by not safely removing the drive as advised. I guess the guy using the drive unplugged it while its was copy data to or from his computer.

When I plugged the drive into my computer, it could be recognised as "local disk" with "RAW" file system with both used and free space at 0 bytes.

How can I recover the hard drive in this state?

How can i recover the hard drive in this state?
Hmm, you maybe don't. What OS are you running? Can you see a partition in Disk Management or your OS's disk tools?

I am running XP SP 2

The drive is not displayed in disk manager, but this gives me an idea to test the drive on another OS, what do you think?

I would pull the drive out of the enclosure and confirm its physical operation by installing it directly into the machine and then using the drive manufacturer's diagnostic software from a boot disk for non-destructive testing. If it checks out, the enclosure may have an issue.

All right, will try it out!