I updated to 7 and rebooted. Box message on screen said to click on “Finish” to complete. I click and box goes away. Every time I turn on computer, this box appears again. When I go into Avast program, it says system is secured and shows version as 7.0.1408 but “not connectd to any Avast account.”
There are several threads on this already. Just look into them, at least one is bound to have a link to someone explaining this problem.
To correct corrupt updates, http://forum.avast.com/index.php?topic=94514.msg752850#msg752850