scenario: father has pc running windows 95, father does not do backups (even after having been told a gazillion times, and having been given a cd burner for that purpose

) His computer will not load windows, it says that the registry cannot be loaded.
I have managed to talk him into starting windows in safe mode, and trying to restore the registry, but this does not work. He can get into dos using a bootable floppy, but not much else.
I got him to run scandisk (actually a few times) and it runs for about 20 mins and then hangs. As he lives in england and I live in switzerland it is costing me a fortune in calls trying to help him, and my memory is very fuzzy about dos etc.
Is it possible to get the computer to load and run a clean version of windows from his installation disk? (I have tried using the bios setup to boot from the cdrom but it doesnt) Or do I need to tell him his HDD is knacked and kiss it goodbye? Any ideas would be most appreciated.