Hi all. I have Linux Mint 20.3 Cinnamon on desktop. I want to wipe HD and install fresh again. Downloaded latest version, checked sha, made bootable ISO but its not working. In previous thread which I cant find someone said it was maybe the usb sticks I was using. Having tried lots of different things, I gave in and bought a new one. Formatted it and wrote ISO from the desktop in question, not working. Repeated same process on a macbook...still not working. I boot from the USB, it says Loading Operation System but then just boots into existing Mint OS on desktop. What am I doing wrong?? Any help much appreciated. Thanks