I have figured it out! It seems that for some reason my external sound card and its drivers were clashing with PP2. So I formatted my PC, turned on my on-board sound card in the bios, re-installed XP SP2 and all the standard essential drivers, then just installed PP2, and it all works perfectly.
Now all I need to do is figure out how to re-install my external sound card so I can start using Pro Tools again.
Any ideas?
Thanks to everyone for upir help so far…
Will