Based on the official system requirements posted on the official website, the CAM2 wasn't designed to be compatible with Windows 7. You have the possibility to install it in Windows XP Service Pack 3 (32bit only), Windows Vista (32 or 64bit), and Windows 7 .(32 and 64bit). There is no Windows 8.1 mentioned on the page. You can find additional information on the following website: http://www.faro.com/products/faro-software/cam2-measure-10/system-requirements#main
However, if you have the setup, right click it and select Properties > Compatibility. Choose one of the supported versions (see above!) and then attempt to run it as Administrator and it should work.
Note: Use a 64 bit operating system to increase compatibility and processing power.