It certainly looks like it does come from avast, although I have never seen this previously.
TeaTimer is a resident element of Spybot S&D if you don't know what it is you are unlikely to be running this, it isn't part of the free Spybot S&D.
That is strange English Text and French buttons.
I would do roughly as you suggested, uninstall avast, reboot, if you have any resident element to Spybot S&D disable it and also disable a-squared. Install avast, reboot.
If you have winXP I would suggest downloading
Ewido Security Suite, I think it is better than a-squared and run it, preferably in safe mode.