Well the Pro trial version should continue to run even after the 60 day trial, but a) it will display pop-ups to notify the end of the trial, b) you won't be able to do any VPS (virus signature) Updates, but it should still run. So there appears to be something esle going on.
avast has a plug-in for MS Outlook which could be disabled, but personally I don't think it worthwhile chasing that for now as it is a minor issue compared to the real problem, why avast isn't running.
I would suggest a clean reinstall and then enter the key:
Download the latest Pro version of avast and save it to your HDD, somewhere you can find it again. Use that when you reinstall.
Download the avast! Uninstall Utility,
find it here and save it to your HDD.
- 1. Now uninstall (using add remove programs, if you can't do that start from the next step), reboot.
- 2. run the avast! Uninstall Utility, reboot. If step 1 failed it may be necessary to run this from safe mode, once complete reboot into normal mode.
- 3. install the latest version, reboot.