Windows 7 not detecting external HDD

We had an iOmega External HDD with network access' hardware die, so we got an enclosure... We have some troubles, the drive shows up in Computer Management, but not in My Computer. I am a hardware guy, software is my weakness.

 Any ideas? I'm fairly stuck.

Can you map the drive from Disk Management?

 

I have problems with HDD's aswell. I have 2 WD Passports. exact same make and if one goes in, I have to remap for the other or I end up with conflicts. Windows thing.

Surely you can just map it in disk management and worst case have to right click and force it into being an active drive?

Well, in disk management I have no options except to delete the volume... Everywhere else said just to map it, that's why I came here.

you cant change drive letter and path? what format is the drive?