Is it possible to swap the OS when booting the computer?

Question

Operating Systems

Good afternoon, it costs 2 OS, but lately I need more 2nd OS, but it is in the 2nd queue and if you do not select it manually, after waiting 10 seconds, the 1st OS is loaded.
Is it possible to swap them when choosing to boot the OS, so that by default the 2nd one comes in first place and is loaded by auto-selection?

Answer 1

Can. I currently have Ubuntu 16.04 and Windows 10 side by side. To change the order of the OS in the boot window, I use GRUB Customizer