Why Does Windows Require Excessive Rebooting?

psxndc asks: "Ever since I installed the Detonator 3 drivers for my TNT2 card (under windows), I've been having issues with my TVTuner card. I've tried installing older drivers with minimal success. The drivers are easy to select between in the Adapter menu and after rebooting my machine for the umpteen-millionth time, I began to wonder 'Since drivers for the display are so modular, why do I need to reboot my entire machine each time? Why couldn't I do the equivalent of just killing and restarting X?' Why did Microsoft (and other OSs for that matter) make the GUI totally integrated with the OS? There must have been a reason. They could have still kept the modules (kernel, GUI, etc) proprietary binaries and not released the source, so control can't be the reason. What is it then?"