The demo download is an executable file. Save it to your Desktop and click on the icon labeled MW3 Demo.exe/TW3 Demo.exe/PW3 Demo.exe. The demo will install and leave a shortcut on your desktop. The IST Demos runs on Windows XP, Vista, 7, 8 or 10.
NOTE: If you are unable to download one of the demo packages, please call 800-835-2611 to ask for a CD or USB copy to be mailed to you.