This is the screensaver Flurry.

The same is true for Flurry32.

Download and unzip.

Just put the unzipped file in Windows (C :) → Windows → System32.

Make sure that "Screen Saver Settings" is open.

「Screen Saver Settings」 is located at the bottom of 「Taskbar Settings」→ 「Personalization」→ 「Lock screen」by right-clicking on the taskbar.