setting up an adhoc network like the link above describes can be done on any computer with a wireless card. any other computer(s) with a wireless card can then connect to it, including laptops, etc.
as for the limited user thing, all depends how your school have setup their policies. chances are it will work, as its a usb device. you will need the drivers though. i wouldnt personally suggest you do it though. i got into a lot of trouble for messing about with my schools network.
as for the limited user thing, all depends how your school have setup their policies. chances are it will work, as its a usb device. you will need the drivers though. i wouldnt personally suggest you do it though. i got into a lot of trouble for messing about with my schools network.