ATI Catalyst tray tool has a useful screen resolution changer. The problem being I set this to a resolution that was much too high and the screen became a mess of moving horizontal lines, unable to change the thing back.
On rebooting, I found the resolution back to normal and everything was readable. That was until I logged in under my girlfriends profile, and the setting was resolution went back to its garbled form.
I knew how to fix this in the past, but after being out last night and my brain not in top shape, I let google try to answer this for me. Suprisingly it was hard to find a solution but this site had the answer:
Basically it says reboot the PC, press F8 before windows kicks in and select VGA mode. Once you can see things, you can go and change the resolution to something you can see clearly.