Hard Drive keeps losing letter.

Hard Drive keeps losing the letter assigned to it anytime I turnoff/restart computer.
I've taken it out and ran it as an internal and external, it does the same thing on another computer.

I've copied everything off of it and did a long format and after some other tries 2 quick formats. The drive retains data but not the letter, when I used Disk Management.

Western Digital Caviar Black 500GB

Untitled Page

Please help

Sardonicus said:

https://www.sevenforums.com/tutorials...ndows-7-a.html

I've tried this as well and it hasn't worked.
The drive was originally on a Mac, but I formatted it so I really don't think it would make a difference, would it?

Any other thoughts?

*Update - I solved this problem by Zero Filling the hard drive, delete all the data and then perform the zero fill.