I'm not an expert on really anything, but if you are one of those (like me) who are using Photoshop and Lightroom and are JUST able to run these programs under your current Windows OS (Vista, 7, 8.1) because of hardware limitations (like just enough RAM and so forth..), think about not upgrading to the FREE Windows 10 OS.
You will soon be buying new hardware I'm thinking. Win 10 uses waaaaaay more Ram. If some geek out there can tell me how to fix it, I would be so happy. I am locking up and can't open Lightroom and Photoshop with any real success.