Okay, so I own the keyboard, monitor and mouse. I checked the wiki, but was unable to find anything about constructing a PC on there. What else is needed for constructing a PC?

You need the case.

- https://www.subetalodge.us/index.php?type=view&item=Black+PC

You need

If I remember correctly the Computer Geek used to give them out as a prize.

Ahhh I see thanks!