ok i think iv solved it. what i have done is bought a USB card bus and used that to connect my harddrive and it works so therefore it must be my internal usb. Any ideas how to fix that??
if onboard usb fails there is nothing much you can do other than replace the board however if other USB components work on it and just the hard drive doesnt a driver or something got corrupt. as long as its working though i wouldnt worry about it.