I used to get that fucking error all the time. Wouldnt let me repair it either. So most of the time it would result in a full system restore - usually meaning i would lose all my data. But it would always be backed up. Then it happend again, but my laptop wouldn't allow it to restore. So i called it a day. Weird thing was it happend from day one, and quite alot of times in truth. I think it was a design fault in the laptop.
But for yours if it is only the first time, there are alot of sites you can find via google which should help. But i would advise you make sure you know roughly what your doing.
And good luck :)