On Intel-based Mac computers, you can install any operating system available in the list of the supported operating systems. If you have a Mac with M1 chip, visit this article: KB 125375.
Install Windows 10
Windows 10 can be easily downloaded via Parallels Desktop at the first Parallels Desktop start.
Click on the Parallels icon (||) in Mac menu bar > New... > Get Windows 10 from Microsoft > Download Windows 10.
To get detailed instructions on how to download and install Windows 10, please visit the article KB 4729.
To get the installation image for Windows 8.1, visit the page to Download Windows 8.1 from Microsoft.
To get the installation image for Windows 7, visit the page to Download Windows 7 from Microsoft. Please be advised you need a key from Windows 7 to download the ISO.
In Parallels Desktop, you can download a set of ready-to-go Linux virtual machines from the main Installation Assistant menu:
To install another distribution of Linux, you need a bootable ISO installation image. Once you get it, click Install Windows or another OS from a DVD or image file > click Continue > choose your installation image and follow on-screen instructions to proceed with the installation.
You can install a macOS virtual machine using the Recovery Partition with Parallels Desktop:
1. Open Parallels Desktop.app from the Applications folder and select File > New.
2. Scroll to the right under Free Systems > select Install macOS X Using the Recovery Partition.
3. Click Continue and proceed with the installation.
To install macOS virtual machine using the macOS installation .app or get more information regarding the installation process, please visit KB 125105.