Windows 32 and 64 Bit

Interestingly, Microsoft, in all its experience, has not been able to streamline the transition from 32 to 64 bit with the experience of transitioning from 16 to 32 bit. Further, the .NET framework cannot run both 32 and 64 bit versions simultaneously. Irregardless of this fact, many applications are written in "classical" applications that don't support 64 bit installs at all.

Personally, I could care less about the "bittage" of the app. I find it demoralizing that a 32 bit windows os is limited to 3.25GB of ram.