How often should System File Checker (sfc scannow) be run? As often as you identify that WIndows has a fault. or if, as the SFC tutorial suggests, "some Windows functions aren’t working". there would be no point.

The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache. … The scan results will be shown after this process is finished.

Actually.. yeah. They fixed some borked DLLs on a server that had some issues. One reboot later and the issues where gone.

While CHKDSK scans your hard drive and SFC your system files, DISM detects and fixes corrupt files in the component store of the Windows system image, so that SFC can work properly. … Once the scan and repairs are complete, restart your PC and run SFC again to replace your . . . Read more

The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache.

Administrative privileges are needed to make changes to the operating system like saving and registering DLL’s is system files, making changes to the Windows Registry or updating Windows core files. The reason you are now asked for to provide Administrator privileges is for better security.

To run as Admin, right-click the shortcut you normally use to start OBS and select ‘Run as Administrator’.

Nvidia’s ShadowPlay can have up and down performance depending on your PC configuration. But it’s free, easy to use, and can be tweaked for straight-up recording, grabbing the last few action-packed minutes of your game, or broadcasting your adventures on Twitch.

Shadowplay shouldn’t cause you to lag.

If you are running shadowplay features like instant replay, record, or live stream then yeah, it will affect FPS to varying levels depending on GPU.