PSA to anyone restarting their PC any time soon: you might be in for a lengthy wait before you can log on again. But there's a very good reason for that: Windows 10's second big update is rolling out to machines across the world as of today. It includes a new app called Paint 3D, built-in game streaming, updates to Microsoft Edge, and a Game Mode that actually genuinely benefits your frame rates.
Your PC will eventually get the Creators Update as part of its regular update cycle, so if you're not especially fussed you can just wait for it to update in the normal course of your Web browsing and whatnot. If you want it now, you can force an update by downloading the necessary files directly from Microsoft.