In what follows, we’re going to show you, in as simple a way as we can, how to apply third-party themes on Windows 10. You’ll have to go through a few minutes worth of tinkering about to ready your system for these themes, and that’s probably why you’re here. The only problem is, Windows doesn’t allow you to apply these third-party visual styles. by default. You’ll find a small fortune of themes on DeviantArt, in particular. Looking to try your hand at applying some custom skins to Windows 10 but don’t know where to begin? You’ve come to the right place. Windows 10 might not have been around that long, but there are already quite a few fancy third-party themes out and about on the web.