Believe me buddy 64-bit Windows = exactly the same stability as 32-bit...
Never saw,read etc anything like that in my entire gaming life...plus you will have more memory for your games...

Also have in mind that all 32-bit client versions of Windows (not just Vista/XP/7) have a 4GB
address space (64-bit versions can use much more). That's the
theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.That's because some of that space is used by hardware and is not available to the operating system and applications.The amount you can use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.