I have an elderly Vostro 1510 (OS Vista) which, whilst rather slow, was working fine when, a few days ago, it suddenly started freezing after a few minutes use. Since then, I've moved a lot of files onto an external drive to free up space on the hard drive (which necessarily took several lots of switching off and on again to achieve) but it has made no difference. I tried using the Vista CD to repair but it didn't seem to do anything useful. I have tried system restore but it doesn't seem to be functioning properly and won't let me do it. I'd be grateful for any suggestions.