system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: why do I have to "restart computer to finish installing"?
gpt
You usually don't anymore, especially if it's a third party program, it's just a holdover from an older era.

 If it's system related updates? Usually because it wants to update files that can't be updated in place as they're always in use. Imagine trying to upgrade a car engine while it's driving, for example. Restarting gives in the chance to do the updates before bringing the whole of the system up.