Just had a power cut. After reboot, my external drive does not show up in the 'my computer' bit. Its recognised because it is in the start bar on the bottom of my screen, but have no way of accessing it. Looked in computer management to see if it needed formatting, but its not showing up there either. Worried I've lost all my files on there completely. If anyone can help me out, please answer in very basic as I am not really computer minded. Much appreciated.

HAve you tried another proper reboot ?
Failing that check it has power and unplug it from the USB wait a few minutes and then plug it back in again.
It should be detected and useable.

Tried reboot. The external hard drive icon still appears in the start bar but nowhere else. In disk management it shows my c drive on the right and the dvd rom drive. Nothing else.

You'll need to try it in another machine if possible, sounds broken to me!

Thanks. Tried that too. Same result. So no way of helping it then? Is it dead or can it be formatted? (maybe not, if its not showing up anywhere)

Probably worth a quick email to the manufacturers explaining what happened and hinting at a replacement (is it within warranty?). They should tell you whether it's likely to be fried or not.

I'm guessing that the problem came from a small surge just as the power went off, do you have surge protection?

Yes, it was plugged into a surge protector. I had thought about trying to return it to the shop as its less than a week old, but I live in Spain and the language barriers a bit of a problem.
I did look under system management, where it shows up with an exclamation mark. Tried uninstalling and reinstalling, followed troubleshooter and also tried updating driver, but with no result. It gives me an error (code 10) message.
Thanks for all your help anyway.

Hi, firebird,
Microsoft help site says the Code 10 is a message received when the drivers need updating.
But, since you have tried that already, there is one more thing to try.
It may be possible to remove the device and redetect it using the Add New Hardware wizard.
You may have already done that, too, by your words of "uninstalling and reinstalling".
If that doesn't work, then I agree with either emailing or phone calling the manufacturer. It could be bad.
Best of luck.