You’ll need to switch the priority level after every bootup unless you use a third-party app like Prio or Process Hacker. Note: Windows 10 does not save the setting after shutting down. This method might not do wonders for your Steam download speed, but at least it will prioritize it over other processes. You can also use the Task Manager to assure maximum download speed on Steam. Right-click the process, then select “ End Process Tree.” Be patient as it often takes time to remove it from the list.
Open up “ Task Manager” by pressing “ Ctrl + Alt + Delete” and selecting it or by simply pressing “ Ctrl + Shift + Esc.“.