Norton Antivirus 2005

My parents-in-law pc licence for Norton Antivirus ran out a couple of days ago so they purchased the upgrade to 2005 which they downloaded but then couldn’t work out how to install as it needed the old version (2002) uninstalling, and then setup running on the new version. I used ultravnc to do all the work on their machine until I had gone through all the setup and then clicked on the reboot option (for about the third time) and now I can’t get back into the machine as the antivirus software comes with “worm protection” – a basic firewall that is now blocking access to their machine. I now have to wait until they get home and can see the email that I’ve sent asking for them to ring me so I can talk them through allowing me remote access to their machine.