So yesterday, when I went to someone else in our office to look how their pc build ended up, I decided to help them setting up windows
All pcs there are on windows 7 except for personal laptops, which I left home because I rarely need it there my colleague was working on his laptop though, so I was obviously gonna use a Windows 7 PC.
I didn't want to use 3rd party software, not because I'd think they're bad, just because I did it with the cmd a few times in the past, so I erased the USB stick and made it bootable, after that I remembered that win 7 can't mount drives without 3rd party software, but tried stuff from the Internet about xconfig, it didn't work (also I got a bit off track trying to automate some stuff of it with a .bat file cause I got tired of doing it manually)
After hassling with it for 2 hours I told my colleague to give me his laptop, mounted the drive and copied the stuff over, plugged it into the other pc and started the setup.

What annoys me is that I didn't even think of just opening the archive with 7zip or something and moving it over, or using Windows 10 in the first place...

Further, I tried to make a multiboot USB stick with different OSs today, 15 minutes of Google and a bit less for actually getting the stuff on the drive and I was done, my stupidity and stubbornness won't get in the way of installing Windows does anymore...