system
Given the following post, respond as if you're commenting on Reddit:
human
Why do I need to restart after installing things and making changes to windows sometimes?
gpt
It's sort of like changing a tire on a car.  You can only do that when the car is stopped, never while driving.

If parts of Windows are in use, it's hard or impossible to replace them with updated versions.  You have to wait until they're not in use.  Sometimes that's as simple as closing a program.  Other times, it means rebooting the entire operating system.