Why cant i install google chrome?

i tried to install google chrome because i want an extension thing that i saw, but when i try to install and when it tries to connect to the internet it stops and a pop up comes up and sais the installer could not connect to the internet, ensure that your computer is connected to the internet and your firewall allows googleupdate.exe. to connect and try again. why is it doing that, my internet is working fine. but how do i look at the firewall to see about the googleupdate.exe thing????