XP IE7 crashes on start

Hi,

I've had an issue with IE7 where it crashes as soon as it starts. I click the 'don't send' button (my habit) and then DrWatson crashes. I then spent all morning uninstalling everything to do with IE that I can. Rebooted, reinstalled using windows update and exactly the same problem. I can't even access the 'Advanced' tab to turn off extensions (I only use Web Dev toolbar AFAIK).

Any ideas? I really don't want to reinstall and have to set everything up again, as I do web development and have spent literally days setting up so I can use different browsers for testing.

I've now got XP pro, SP3, IE7. IE6 runs in a standalone mode. Firewall is off as we use a server system with firewall for the networks.