Vista no longer recognises my RAM

[erenoth2002]

Hey I was running an hp computer, with an AMD phenom 9500 quad processer with 8gb of ram on Vista home edition, while it was only recognising 7gb that was alright with me It was running alot faster and smoothly, however, i picked up the Vista ultimate upgrade and installed it only to find that now its only reading 3gb of ram .

So do I need to return to my previous installation? or is there anything that i can do?

[dontgvadamn]

did you get the 64 bit version???? the only way the OS will recocgnize 8 gig of ram is with 64 bit OS. 32 bit will only read 4 gig...and you wont actually ever see the total 4 or 8 gigs.