Okay i see that you said when Windows was installing you had a bunch of errors. Now did you install some new hardware recently? How old is this computer? If you installed some new harware and this started to happen it sounds like what happened to me. I had so much stuff running and not enough juice from my power supply. So if thats the case you can get a new power supply and that might fix the problem like it did for me. Now if the computer is old and you havent done anything new with it then i would have to say your hard drive is trying to tell you goodbye cause it is about to kick the bucket.