Hi, I purchased a 320GB Neso external hard drive about a year ago to use as backup for my macbook and it has worked completely fine up until last week!

It was becoming full so I decided to delete some of the old backups on there and since then the macbook doesn't show the drive now when I connect it. It still has power as the drive is working but it doesn't show anywhere on the macbook. I also tried it with my desktop PC and again there was power but could not find it.

I am not sure what I have done or how to rectify it - I would like to format it and start using it again but it's quite difficult to do when no computer is reading it

Any help would be great on where to try and locate it from the macbook, I tried disk utility and it doesn't show there so not sure what the other options are?