Hi, I haven't used Houdini in a long while, but I notice that when I check my Task Manager, every once in a while hserver.exe (more specifically, the process “HoudiniServer”) will be running. Is it launching on startup automatically, or even just starting on its own after a set period of time? How do I stop this if this is the case?

It's a service, so you can shut it off if you like (though Houdini will no longer run while it's off). Run msconfig, and in the Services tab, find the “Houdini License Server” and “Houdini License Client” services and uncheck them.