I was having a tidy up (I thought) but when I next tried to boot up it wouldn't. Tried using the Leopard disc and that works for an instal but will erase all on the disc.
If there is no other option that is what I'll have to do, I think I've got most of it backed up.
Its a 150Gb hard disc but was practically full (only 3.5 GB left).
All thoughts welcome.