The download is a self extracting zip file. When the "What do you want to do with this file" screen appears, click on "OPEN". After the AttackAttackSetup.exe file appears, double click it to run the intallation program. Click on "YES" in response to the "Do you want to allow this program to make changes to your computer". When it runs,select the directory in which you want to install Attack-Attack. Hit the UNZIP button. The default installation directory is C:\Program Files\Attack-Attack. After installation completes, an icon will be placed on the desktop and in the Programs tab of your Start menu. You can run Attack-Attack either by double clicking on the icon or from the Programs tab of your Start menu.