Instructions
Insert the game's installation disc into your computer. The installation wizard will appear on the screen automatically. Click the "Next" button and follow the instructions on the screen to select a location to save the game and install it onto your computer's hard drive. When it is finished, do not attempt to open the game.
Right-click on the icon for Rise of the Witch King and click on the "Compatibility" option. A window of options will appear. Uncheck the box next to "Run this program in compatibility mode for" and click on the "Apply" button at the bottom of the window to apply the changes.
Open the folder in which you saved the game during the installation process. Move the entire folder, which will be labeled "The Battle for Middle Earth II," into the folder that can be found on your hard drive under "User," "Your Name," "AppData" and then "Roaming."
Open a browser and locate a Rise of the Witch King Vista patch. Download the patch to your desktop. When it is finished downloading, right-click the icon and select "Extract." A new file will appear on the desktop. Open this file to run the patch that will allow you to play the game.