 How to run a Windows operating system on a Mac computer If you need to install Windows on your Mac, this could be the best solution. Download an image of the Windows operating system. When the ISO image is downloaded, you can begin the installation. Click on Launchpad, open Other, and run Bootcamp Assistant. Bootcamp should find the ISO file automatically. After that, the process of booting software to support Windows will start. In order to avoid having to restart the computer all the time, you may choose to install a Parallels virtual machine instead. Start Parallels Desktop. Select Install Windows or another operating system from a DVD or image file. Specify the version of the operating system. When it's done, you will get a virtual machine running a full-featured Windows.