while having AVG is better than nothing, it is a weak antivirus and there are many better ones out there.
There are a few possibilities. First, reboot and try to open it. If that fails, redownload and try to open it. The original download may have been corrupt. If that also fails, you may have a virus that is preventing it from opening properly.
To get around this problem, download Avira AntiVir Rescue System CD, and burn it to a CD (the software to do this is included in the download). Reboot the computer to run this disk, and it will remove the virus bot that is preventing AVG from opening.
Avira AntiVir is a much better virus program than AVG, and is free.
Unfortunately, you will always be most secure with paid antivirus software
