Make sure that you install from an administrative account.
Download the installer again and use the new file to install.
In some cases, an installation may look frosen for a few minutes. It's normaly caused by the installer needing to wait for some other process or service to finish some task on some resources. It's normal and the installer will continue normaly once the needed resource have been released.
I had a rather long pause about when you describe when I installed AVG Free in my Windows 7 computer.