A game still cannot use more than 2gb of RAM on a 32 bit system. Trust me sir, I've done a ton of research on this during my Supreme Commander days.
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http://msdn.microsoft.com/en-us/library/aa366778(v=vs.85).aspx
The most RAM an application can use on a 32bit system is 3gb, and that is if you're running the 3gb switch
and the application being run is large address aware.
Yes, a 32bit OS can access 4gb of RAM total, however it's split in half, 2gb for the user space and 2gb for the kernel space.
Umm ... 4GB is the max addressable by 32 bit, but in practice its a bit less, around 3.5GB-3.8GB ...