Old box, new install, Grub fails error 18

[David]

I have an ancient HP that I've just installed Ubuntu. It reached the end 
of the install, then choked on the re-boot with Grub "error 18". I think 
this may have to do with a bios problem, and if so it's not worth fixing. 
I just get another box that isn't quite so ancient ;-)

Two questions:

* Does error 18 refer to a BIOS problem? If so what?

* Can I take the hard drive and put it into another machine without having 
to reinstall?


Thanks...

David