Sometimes you just need to prevent your computer from entering sleep mode. Maybe you don't want to have to ask your supervisor to log you back in to the lab computer between every run of your experiment. Maybe your institution's IT policy is to have all machines enter sleep mode after 3 minutes of inactivity, and you're sick of having to log back in every time you take a sip of your coffee and write down a note on paper. Maybe you've written some poor code for an obscure application and you don't have the time or skills to make it better, you just need to keep the silly machine awake for the 3 days of this project and then never touch any of this again.
wakeywakey will simulate a keypress every few minutes to make windows think you're still using your keyboard. Yes, that's right, it's just Caffeine for people who aren't allowed to or can't install other software on their Windows machine.