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However, Windows 7 is by far the best OS for playing 3D games and watching videos. There's no questioning that.
What I do, and what I suspect most people do, is run Windows 8 as my main OS and dual boot all my Linux distributions. If I want to play a game, you just boot into Win8 and go do whatever you want. If you need to do something in Linux, you bring it up. Switching between them takes less than a minute. It's great.
So, no, Windows is not worth uninstalling. I recommend doing everything you can in Linux though, and only switching to Windows when you really need it. The best way to learn how to use Linux is using it on a daily basis.