That response is uncalled for. You can't brick your MoBo using the suggestions that Krypto made. Resetting your MoBo Bios to factory defaults is a simple processes of resetting a jumper or worst case removing the CMOS battery. Many BIOS setting will allow you to do some if not all of what you want, you can disable USB ports, serial and lpt ports, even set CD and DVD drives to "Not Present", relatively cheap and simple process.
Alternately you could and probably should buy a cabinet enclosure that will allow you to secure the computer and peripherals and only expose the touch screen to potential kiosk users. And if you are concerned about the keyboard then you should also disable the Windows 7 on screen keyboard