This iTunes installer is only for Windows 7 and later on 64 bit systems that are unable to support iTunes video playback requirements on older and low end video cards. Only use this installer if you were directed to this page by the below alert message from iTunes 12.2 or later. Using this installer on an incorrect system may prevent your system from getting the correct iTunes installer in the future.”
If you haven’t already, try using the recommended installer first. http://www.apple.com/itunes/download/
If you were directed to this page by an alert from iTunes, follow these steps:
Download the iTunes installer to your Windows desktop
Locate the iTunes64Setup.exe and double click to run the installer
Install as you normally would. Your iTunes library will not be affected.