I did that once, just bc I didnt want to bother turning it off, and any time it senses anything moved, the comp freezes. At least mine does. But that is only taking out one stick (or putting in). I dont know what would happed if you took them all out, my guess would be that it would freeze, bc no data could get anywhere, but everything else would still function. Dont try it, please, like SFR said, it WILL NOT be good for the comp. Whether or not it f's it up, I really dont know. Curiosity killed the cat, and will electrocute a curious human.