Seems to me as a conflicting application is on your computer. Could you check please, whether you are running some other AntiVirus, Firewall, AntiSpyware or similar security program?
I downloaded the free version of AVG 9.0 build 707 to replace AVG 8.
However, having restarted the computer as part of the installation, and tried to connect to the internet, I kept getting the message 'no connection'. I did a System Restore to the previous day, which cancelled the download, and everything was fine again. I have tried to re-install AVG 9.0 and get exactly the same results. I have been using Google Chrome for internet access - is this part of the problem? I would appreciate any help.