My iomega external hard drive light keeps flashing and not registering on my computer.

[icklefrog]

I have the correct power cable but the light my external hard drive (iomega 500mb) keeps flashing is not appearing on my computer.

 

[Phillip Corcoran]

Check to see if Windows has assigned a drive letter to it. Add one if it hasn't:
http://windows.microsoft.com/en-gb/windows/change-add-remove-drive-letter#1TC=windows-7