Peter, Have a look @ this article (http://avgclick.me/restorechangesbyAVGPCTuneup).
AVG Guru
I replaced my original TuneUp with the new AVG Tuneup then promptly performed an AVG security scan followed by a tuneup. Both worked fine. The following day, I could not access Outlook Express Mail nor AVG Security nor AVG TuneUp but received the message that my Calendar was corrupted. Unable to uninstall TuneUp I restored my computer to an earlier date whereupon O E and AVG security worked fine. I have repeated these steps 3 times on different dates to satisfy myself that TuneUp is causing the problem. What is the remedy?
Peter, Have a look @ this article (http://avgclick.me/restorechangesbyAVGPCTuneup).
AVG Guru