human
How do I install two operating systems on one computer?
assistant
Install Two Operating Systems on One Computer
1. Download and install Rufus from https://rufus.ie/.
2. Download the ISO file for the operating system you want to install.  
3. Use Rufus to create a USB install disk from the ISO file.
4. Create a partition for the new operating system in Disk Management.
5. Disable Fast Boot in the Windows Control Panel.
6. Boot into the computer BIOS and disable Secure Boot.
7. Set the Boot order to boot from the USB drive first.
8. Boot your computer from the USB Install disk.
9. Select your language and keyboard layout.
10. Select the "Custom" or "Other" install option while installing the new operating system.
11. Select the new disk partition and format it.
12. Follow the instructions to complete the installation.