Been Running for 60 days, 64bit (legit version that is the RTM).. ONLY issue i have run into, is installing Vmware Vsphere client. (Vmware issure not MS) workaround avaliable.. OTHER THAN THAT, every game, every other box application just works veryy, veryy well. USed vista since day launch of it, and there is indeed a difference. Subtle, yet extravagant. Finally a 64bit os, at right time/ quad core is cheap, ram is still cheap, 1.5TB drives at $115.. Right place/time for it