Ok, thanks. This did eventually work. I first tried a new install to the desktop using the disks, and it had the same freeze on start-up. The second time I used the downloaded installer and the cds to install to the desktop and it is now working.
Though, this kinda sucks that it has to be installed on the desktop rather than in a suitable directory. Imagine if every program needed to install to the desktop, what a mess that would be.
But, thank you, at least I'm flying 10.50 finally.