It all depends on the source of the installation. If you have the setup file, simply launch it using a username with Administrator rights and follow the on-screen instructions. If you posses a DVD, insert it into the DVD-ROM, and the autorun will start. Once the installation window appears, continue to installing the game and input the serial number printed on the CD/DVD sleeve and that's it. At the end of the installation, start the game from your desktop. The CD/DVD needs to be in the CD/DVD-Rom while you play or start the game.
