Computer Turns off when playing SRB2

Whenever I'm hosting a server, my computer ends up turning off itself.

Any reason why, cause I'm really getting sick of it doing this.

Maybe something inside the computer is getting overheated. Same thing happened to my old dad's XP laptop.

Yeah, I had that same problem with my old ´96 computer, it is the computer firewall, if your computer is not an uber fast0rz 9000, the firewall, combined with the information sent when a player joins the game, makes the computer overload and shutdown. Just try desactivating your firewall or antivirus, it should help.

Your computer overheated, mine did the same 2 days ago. You have to make sure you either close your laptop or turn it off since it is normal for laptops to heat up after a period of time.