I would like to try Ubuntu, by installing it on a USB (flash) drive. The instructions say I need a Ubuntu ISO file on my computer but when I follow the link given, the first option is "Install Ubuntu and REPLACE Windows" Zounds! I don't want that, there seems to be no option there that says "download the ISO file". How do I do this? I have already installed Rufus and I am "all ready". How about a clue.
You can download the Ubuntu ISOs here: Ubuntu.com/download/desktop
After installing the ISO onto your flashdrive, plug the flash drive into your computer and boot from the drive (you may need to look up how to do so for your particular system, but repeatedly pressing the 'Delete' button should bring you to the BIOS menu, where you should be able to select your flash drive from the boot menu).
After successfully booting from your flash drive, it should present you with a screen like this:
Simply select "Try Ubuntu" and nothing on your hard drive will be altered. Simply remove the drive and reboot and your Windows instance will resume as normal.