why so many asks this
?
i wanna know too

I dun think it's possible 
Gonna just play minecraft instead xD
it is possible, i did it 6 months ago before my school started to get a programm which blocks those .exe datas.
but before i put RO on a 4 GB USB Stick, and played on a School Computer but it lagged like hell because of
the school internet and Computers which has bad Grafic.