recovery disc hanging...?

I yesterday purchased a recovery iso for Vista to hopefully fix a Windows not loading problem on a laptop.
Successfully created the disc and ran it. The software loaded ok and went through several stages, but is stuck on "checking registry for known issues" - I even left it running overnight but this morning no change.
The laptop would only load to the black screen with the start options "safe mode", safe mode with networking" etc (excuse my lack of tech on these issues!), and on selecting a boot option would just return to the same screen after a short time.....
Any suggestions welcome.