sorry i stumbled across this post and am intrigued! I thought that 64 bit and 32 bit was all down to hardware and there was no chose over how many bits you could run. Over the last year I have updated various bits(as in parts!) of my desktop i am resisting the urge to go to vista just yet I would need to upgrade my video card and that now means motherboard I'm on all my old one can manage but could I go up to 64bit xp? Is it worth it? What would I need to check? For the record i currently have a pentium 4 3.07ghz and 1.49gb ram memory, a radion 9250 graphics card.