Warty install went very wrong HELP!!

[Baza]

After doing the GNU/Linux hard sell to a friend he asked me to install
Ubuntu on his Windows PC. He wanted to keep windows because he has a lot of
Uni work on it.

After installing Warty Windows no longer works, it starts to boot but then
displays the message, AUTUCHK PROGRAM NOT FOUND: SKIPPING AUTOCHK. It the
blue screens.

I really need to know how to get Windows back on his box.

Baza