Tony - yes, I have suceesufully used the "clone onto new disc and repair" technique.

It is reliant on your hard disc faults affectingv the windows system areas of the disc rather than the extra stuff you have added to it. I consider it worth a go because you are not doing anything to the original disc (other than trying to read it) so if the repair (on the new disk) fails the situation should not be any worse than it was when you started.

In my case it took the clone operation 3 days to copy the failing disc, I was lucky that the faulty disc actually had very little data on it and most of the bad sectors were unused.