Running the GeForce Experience Overlay without signing into GeForce Experience - ElPumpo/TinyNvidiaUpdateChecker GitHub Wiki

If you have installed the GeForce Experience you can find the overlay program at the following location:
%appdata%\Microsoft\Windows\Start Menu\Programs\Startup\NVIDIA Share.exe

Create a shortcut to launch it when you want it or put a shortcut in shell:startup to start it when logging into Windows.

If you're worried about GeForce Experience collecting data you can edit your hosts file to block communication with Nvidia servers. It is located at this location:
C:\Windows\System32\drivers\etc\hosts

Put this below the commented lines starting with #, save it, and reboot:

0.0.0.0 ls.dtrace.nvidia.com
0.0.0.0 telemetry.gfe.nvidia.com
0.0.0.0 accounts.nvgs.nvidia.com
0.0.0.0 accounts.nvgs.nvidia.cn
0.0.0.0 nvidia.tt.omtrdc.net
0.0.0.0 api.commune.ly
0.0.0.0 login.nvgs.nvidia.com
0.0.0.0 login.nvgs.nvidia.cn

If Windows tells you that you don't have permission to do this, save it elsewhere then remove the .txt extension from the file and copy and paste it where it needs to go to overwrite the old hosts file.

This trick combined with this makes it completely unnecessary to login to GeForce Experience as you can update drivers automatically and open the overlay without doing so. The only thing you need to login for is if you want GeForce Experience to automatically set game settings for you but using this feature is highly discouraged. You will almost always get a better looking and higher performing game by learning what the display and graphics settings do for that game and setting them accordingly.