I'm not up to date on the 64 bit technologies, but... Last I heard the Athlon 64 would work on the 32 and 64 bit Windows OS AND run 32 and 64 bit applications. The Intel alternatives were reportedly incapable of spanning the technologies, forcing a person who wanted to get the 64 bit Intel machine to upgrade ALL software & OS to 64 bit. All or nuttin' sucks for poor people. Has Intel solved that dilema or are they still sitting on their 64 bit chips?