Shift 2: Unleashed installation stuck at approximately 23%

Yesterday, an Associate whom I visit every Monday & Friday has told me he got Shift 2: Unleashed, however he says that he can't get the game to install.

The Key that came with the copy of the game works, I can start up the Installation set-up, put the Code in without any problem, however when the game is being Installed, the progress stays stuck within less than 3 seconds at the quarter-way mark. It has been stuck like this for a whole hour and cancelling the installation doesn't cancel it. We had to resort to opening Task Manager to end the installation window.

We're trying to install the game on a Windows 8 system, in case that helps with anything. So far, nobody else seems to've reported this issue, only us.