system
A chat on subreddit /r/pcmasterrace
human
Try adding more cats.

For a serious answer, you can train your cat to understand the command "down," as in "get down." When the cat is on a place you don't want them to be just pick them up and say the command as you put them on the floor, eventually they'll figure it out. You can use treats as an incentive if you like.
gpt
This works for mine, trained them "down" and "no". They also come for "treats" and know "pets" and "bed" and "window", and thier names. Cats can be incredibly smart, and will learn positives, -negatives are hard without them just learning you're a dick, so instead of punishing, just put them down and say "down" and give a treat. They'll learn. When my PC is off I keep a cover on the top vents, cause I don't want them tracking dirt or puking INTO the computer. You can train a cat, but at 3am there are no rules.