This error typically occurs when there is more than one installation running simultaneously. In order to run properly, there can only be only one installation running at a time.
Take a look at the Microsoft Windows Taskbar (this is the bar generally located at the bottom of your screen that holds your Windows Start button and the clock) and cancel any additional occurrences of the Quicken installation process that are running (also check for any other programs that are being installed). Attempt to run the Quicken installation process again.
If the error code persists, restart your computer and attempt to run the Quicken installation process again.