Ok so i bought a new PC today so i can effectivly run 4 shamans

AMD Phenom 9550 Quad core processor

6 gig of memory

Windows vista home edition

I havnt opened the box yet my question is...Is windows vista home edition is that 64 bit or no? If not will it not recognize the whole 6 gig of memory only 3? If so would it be better to return the pc i got for one with 64 bit windows vista. I await your answers. thanks a bunch