I have downloaded Ubuntu 15 (32 bit) on a flash drive, I migh burn it on a DVD too if necessary, and I have noticed the question asked in here five years ago,
-which has a very clear guide for installing in its answer, thank you for that!
Windows 10 seems very invasive, are there any known issues for installing a clean version of Ubuntu without keeping Windows?
edit: I do not want a dual boot, only Ubuntu.