By default, Windows 10 Screen Saver will start displaying saved pictures that are on your computer, some users may not want this default.
Step 1: Open Settings app. To open it, open Start and then click Settings. The Settings app can also be launched with the help of Windows + I keyboard shortcut.
Step 2: Click on Personalization category to navigate to the same.
Step 3: On the left-side, click Lock screen to see Lock screen related settings on the right-side.
Step 4: Scroll down to see Screen Saver Settings link. Click on Screen Saver Settings link to open the classic Screen Saver Settings dialog.