Windows 10 has been reviewed as a terribly insecure operating system, and one of the main reasons is all the ways it communicates back to Microsoft. These lead to ways hackers can get in to your system. By turning off dozens of non-necessary features you can harden your PC's security, stop Microsoft from spying, and even possibly speed up actions on your PC. Just be careful turning off features other than the 'green list' recommended items. I turned off several others for things I deemed safe, but you have to decide this yourself. Changes can be undone if need be.
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