Which OS are you using? I managed to install it on a Win 7 SP1 64bit but I wasn't able to avoid some compatibility messages, even using "Previous version" options. I tried with both Chrome and IE browsers, even adding the address to the trusted sites, but with no luck.
I guess it's a discontinued feature, since in NAV 2013/2013 R2 learning lessons it's not available anymore and the installer is not updated since year 2009.