Ive had a lot of people ask about the tool I use for booting OS files. I use a software called Ventoy. It allows you to have multiple OS ISOs on a single drive (the only limit is space) and will load a boot menu that allows you to select the ISO you want to boot from. I have it installed on an external drive for portability. I can take it to any machine, or use for VMs to install the OS of my choice I want to experiment with. Highly recommend Ventoy for those of you that work with multiple ISOs.