License dialog blank - can't register and interface locked up

Phone tech support advised to uninstall and reinstall Avast Internet Security due to another issue about firewall error message/inability to manage it at boot (he said it is conflicting with Windows firewall and so must reinstalled and to then turn off Avast’s firewall to clear the problem). He advised using the Avast uninstall tool and I followed the instructions precisely. Then after reboot installed the latest version of Avast Internet Security. I was able to turn off the firewall now. It went through some set up steps and when it came time to insert the license the resulting dialog box came up blank. Could not confirm license and it was never applied even though it did go through the next few steps afterwards. I tried rebooting and going through the license insertion process again and the license dialog box was blank again. The software shows as running in 30 day trial mode. The blank license dialog now cannot be dismissed nor the main software window. Need help!

Running Windows XP SP3.

Thanks.

See if this helps…

https://www.avast.com/faq.php?article=AVKB157
https://www.avast.com/faq.php?article=AVKB7

Unfortunately, clicking on the license key file directly brought up the same blank dialog box. I had to reboot the PC to clear it and the main window. I am helping a friend with this problem. We then thought to try to insert the activation code instead, but she doesn’t have it anymore. When we logged into the customer portal it only offered to email her the license key, there was no way to obtain the activation code. How can we get that?

Other than that we have no other ideas on how to solve this problem. We are stuck. Can anyone suggest anything else we could try ?
Thanks.

Perform a repair of avast and see if the problem is solved.
If not, perform a clean installation of avast.

Contact support: https://support.avast.com/support/tickets/new