While installing Reference 4 on Windows 7, you might encounter a window asking you to install Windows security update (as shown in the picture below)
(Please note that in order to install the update, you need to have Microsoft Service Pack 1 installed on your computer)
Please press ‘Download from Microsoft’ button, which will take you to Microsoft website and automatically start a download of the appropriate version for your system (32 bit or 64 bit).
Please allow the update to fully download and install on your system. Afterwards, you will be prompted to restart your computer for the applied changes to take effect. Please press Reboot now to restart your system.
After rebooting your system, you should be able to start up your Reference 4 installer by pressing the Run button on the Security Warning message window (shown below).