Windows 7: Avast 4.8 professional license fails after joining to domain

I work at a public school and we have been using Avast 4.8 professional on our XP computers. We are starting to upgrade the computers to Windows 7. I enter the license key and it says thank you. Seems normal until I reboot, and I get a message saying Avast has expired. If I remove the computer from the domain it works fine until I rejoin. Then the I get the error again.

Avast support forums may be able to help you better than we can avast! Free/Pro/Suite

avast! 4.8 is an extremely outdated version, avast! is currently on version 6.0.1289. I read over at the avast! forums that avast! will soon (maybe even now) drop all support for such outdated versions of their software. I highly suggest for you to upgrade to the current version of avast!.

I agree with updating our version but my boss has been happy with this version and can't make up his mind what he wants to do. If I could find a fix I could continue with my work while he takes his time deciding what he wants to do. I also have posted this on Avast forums. Thanks everyone.

Thanks for reporting back, good luck!