Hard Drive not being picked up

[multironin100]

Hi
I have an old hard drive that doesn't seem to be picking up on windows, I think it has Linux on it but not sure if that has anything to do with it, it is an external hard drive so is going through usb. windows makes a sound that is connected but nothing shows up, I know its not the sata to usb bridge because I can use my other hard drive and it works fine, it seems to be working as the disk inside it seems to spin but still nothing is picked up.
Please help

 

[Phillip Corcoran]

Doesn't matter what is on it if it's not a boot drive.

Sounds like it may just need a drive letter manually adding to it:
http://windows.microsoft.com/en-gb/windows/change-add-remove-drive-letter#1TC=windows-7