*cough*Relevant xkcd*cough*
Also
https://xkcd.com/349/Might be said by now, or irrelevent, but most distro installers, that hand-hold you at all, let you resize your Windows partition down and do a boot manager thing that works by choosing the defaults 99% of the time, but backups before you start aren't a bad idea.
In fact, get a install-onna-stick distro something like CloneZilla on a USB stick and make an image of your system (on spare space on that stick or other media bought to be big enough for the purpose). You need to make sure you don't overwrite C: with the (blank) media image, but reading dialogues carefully will help, before clicking away.
The bootable stick will have a (basic, and slightly dedicated to disc imaging) Linux system that you can try shell ('command line') stuff in, if nothing else, and you have the means to backup and restore (if necessary! ...with caveats about losing newer data/etc) your system whenever you like.
Or just get yourself a more general linux-onna-stick flavour, and don't worry about dual-booting or VMing in any way that interferes with your main machine's drive at all, at the cost of a little system speed while you're trying it out.
ETA: Ah, should have read further, work is in progress already. So, windows has iinbuilt partition-management (post-install) these days? Surprised. But then I've long used GParted (or one of its kin, either a dedicated bootable or through a general linux install) over and above anything like Norton Tools.