You're basically telling your computer to stop all actions for every program you ticked off, which may include things like your antivirus program, connecting to your printer, being able to adjust your graphics from your graphics card and so on. If you missed the step to "hide all microsoft services", this would destroy certain functionalities, like even going online, hearing audio and possibly even properly starting up the computer at all.
I personally don't like how this is even a method to casuals. I understand this being a thing to help make your computer run faster, but to help make your character work properly is ridiculous.
The rest of the information is actually new to me, but sounds safe enough. Again, very abnormal method to just make your character work properly, but this makes a bit more sense because (don't quote me on this) it probably deals with resetting data that's possibly jumbled connecting the game to the internet and contains a missing action. I'm sure someone will definitely correct me on the matter, but I digress.
Again, solutions that I personally don't like because now it's tinkering with sensitive information that most players wouldn't understand.