Time machine wont backup

I am posting this for a friend of mine. He is using a WD 500mb Mybook for his Time Machine backups. Every time Time Machine starts, it says the backup volume cannot be found. We have re-formated, re-partitioned the drive, and still no luck.

Any ideas out there?

I am using Time Machine with no problem with the same model drive.

You need to use the disk utility

to find it look it up in
Applications
.... Utilities
........ Disk Utility

High lite your external hard drive on the left hand side of the window
Then Click on "Erase" Change Volume Format: "To Mac OS Extended (Journaled)"
And Click on "Erase"

I think the Format is were your going wrong.

Yep, we did that part already during our testing, and no luck. Any other ideas?

It almost sounds like TM is configured incorrectly. Simple, but did you choose the disk to use, after you reformatted it, in TM's preferences?