I was wondering about "PMDG *highly* recommends the use of 64-bit versions of Windows due to memory limitations in FSX. "If Microsoft FSX is a x86 application, is it going to be able to take advantage of Win7 x64? I have also read some blog sites suggesting that FSX should be ran in XP capatability mode to avoid any problems encountered when upgrading to Win 7 x64.. I thought that since my WiFi reception is poor to fair in the room that I may disconnect the WiFi to possibly avoid problems with FSX/PMDG 737NGX not responding after 30-40 minutes of flight. Regards,Herman K.

The answer to your first question is undoubtedly yes. Remember, a 32 bit system is limited to 4gb of RAM, which of course has to be shared by all applications running on that system. Also, do a search on "virtual address space" if you want to know more about the limits you're facing with a 32 bit OS. Compatibility mode? I'm not sure about this one. I'm not using it, and I'm not having any problems. I don't follow your reasoning regarding disconnecting your wifi. What exactly do you think this will do?

The thing with 64-bit systems, as Sean pointed out, is that a 32-bit system is limited to approximately 4gb TOTAL memory. That's a bit less than 4gb total for the system, FSX, background processes and any 3rd party apps you might be running. 64-bit systems have a far higher VAS limit, which means even though FSX as a 32-bit app is still limited to approximately 4gb, everything else isn't encroaching on that. If you've got 6gb installed, everything else has 2gb, if you've got 8gb installed then everything else has that extra 4gb to use, not hindering FSX's memory usage in any way. Video RAM complicates the math a little bit, but it's still the same principle. Bottom line is with 64-bit systems and 6-8gb ram, FSX gets all the memory it can handle. It won't be stuck competing with everything else. EDIT: I've never run FSX in compatibility mode on win7. I do however always run it as admin.