Hi there.

When it is plugged into your PC via USB and you go to "My Computer", does it recognise it? If not first try using another USB port. Another thing to try is see if you can get hold of another USB to external hard drive connector. Your current cable may be faulty. If you can see the drive in "My Computer" and when you click on it you get a message saying something about the drive not being formatted and prompting you to format then this means that the drive has failed and needs to be reformatted. You may or may not be able to recover your files in this case unless you take the drive to someone local that does data recoveries. i.e. a local PC store.

Go through the above solutions and let me know how it goes. Please feel free to ask any further related questions or clarifications.

~Slasher_X