I have been having the same problem: on several occasions, once before reinstalling it and at least five times a few days after reinstalling it, my avast! Free Antivirus has changed to avast! Pro Antivirus. It then says the trial period for avast! Pro Antivirus has expired and asks me to activate it by buying it, which doesn’t interest me. Then I get a message saying the trial period has expired and that my system is no longer protected.

I am running Windows XP Pro SP3 with no other antivirus installed. I have uninstalled the avast! multiple times using both Add/Remove Programs and the aswclear tool in Safe Mode. Yesterday, the last time around, after doing so I also manually deleted the empty C:\Program Files\AVAST Software folder, I removed previous downloads of the setup tool, I ran ccleaner to remove unwanted files and fix registry problems. And I searched C: for anything that says avast, and deleted those files.

I then downloaded a fresh copy of avast! setup from the avast site. I installed it, got a screen that said I was registered (it picked up a previous registration date). And all was perfect until I restarted my machine. I got a red popup stating: “Your subscription for avast! Pro Antivirus has expired. As a result, the program will not download any further updates.” I then clicked on a link on the popup that took me to a screen that said, “Your trial protection will expire in 10 days.”

I now get a page that has changed from white to the black background for avast! PRO ANTIVIRUS and a message that says “The trial period has expired.” Avast’s red ball now has an X through it. And I am unable to turn avast! back on.

I suspect the problem I am having may have originated when a month ago I may have inadvertently clicked on the green “Upgrade” button in avast! Free Antivirus, having confused it with “Update.” But after several uninstalls and reinstalls the program keeps trying to switch me to avast! Pro Antivirus.

What can I do to fix this problem?

Many thanks.