The Microsoft windows 32bit O/S can only address 2.5gb of ram max using the /PAE switch you can see up to 3.2gb but its more snake oil than a working around.

If you’re planning to run 3 GB or more ram go to 64 bit vista, there’s nothing in the 32bit version of vista that isn’t supported in the 64bit version it in fact supports many more hardware devices and a lot more software.

All of your old 32bit programs work perfectly there’s not real performance benefit apart from properly addressing and using 100% of 3 gb+ ram


If you can run it and your using 3gb of ram or more run it.

xp x64 is a different matter I wouldnt go there unless your willing to tweak.