Steam games auto update issue

[AnsleyCarroll]

Hello Buddies, I have been facing a problem recently. Whenever I boot my PC, Steam starts to updates all games automatically which I can't want all time. And for that reason, my PC runs slow. I want to stop update a particular game, not all games. After searching online I found this article and here suggested to the 4th method about how to disable auto-update for a single game.

If I go with this, will there any problem or my PC will run fast like before? Or I have to disable all games on Steam for running my PC normally.
Any suggestion would be highly appreciated.