Never done it but here is a couple of ideas. 1) build an insulated box around your computer with a hinged access panel. Inside the box wire in a light bulb socket. I bet a light bulb will keep the space warm. I have seen welding rod kept in old refridgerators this way. 2) instead of a light bulb use the wire made to keep pipes from freezing in the box. Either idea could be hooked to an in line thermastat to only turn on at the preset temp.
