This is kind of offtopic, but I must say that Windows 10 is a bad system, it much depends on your version (Home have less options and more stuff to do with sys registry) and how much time/effort you want to spend to disable annoying things. Like running in background anti-spyware/autoupdate/sys memory optimization/and other tools, if you are on gaming/dev desktop machine with i5/i7 it's not a problem but if you are using office pc, or net designed notebook then those applications can consume even 50% of your cpu power (and of course constant disc usage) during you normal work, so pc becomes unusable. Despite that, they start even if you are using notebook without power adapter plugged-in, so...
No option to choose what update you can install is also a pain, as this also is set to periodic updates in background, I prefer to choose one big cumulative update than daily little patches that clog the OS.
Problems with switching graphic on notebooks (between integrated and dedicated), graphical artifacts in games (testing on different drivers versions), total hang-ons while Alt-Tabbing, Xbox DVR that messes even more. Overall system stability (much more crashes, explorer.exe is stable like in Win XP days), and more more bugs, strange design paths...
You can try to fix some issues with dedicated software, playing with registry but disabling one thing blocks/change another (e.g. in Home version disable auto-updates disable whole Windows Update system, so to do manually updates you need to again enable it in registry and so on). And really is this what a good system should look like? To force user to waste time and fix such things...
After updating my OS and one week on Windows 10 I used 'back to Windows 8.1' option, and I'm happy with it.