We need a lot more information than that if you want help. First - is it turned on?
we need alot more information, i don't no why you didn't in the first place is beyond me you have us all guessing which is annoying
the fact most are saying wrong os is quite annoying too lol, this is not true at all unless im missing something, iv got windows 7 x64 lite running well on 2gb ram no problems and it does not matter if you install windows with usb3 drivers as usb2 drivers are with the wim
the question remains what do you mean not installed ? do you have 2gb missing ?
you processor is capable of 64bit operating system use it this way it will shows all ram and utilize all off the processor
if you run a 32bit of windows it will only show you a certain amount of ram, 4gb if i remember rightly and will not utilize the processors capabilities