I always run full screen. Also, if I go to windowed view, I always alt-enter, never alt- tab.I've never had any problems switching between the views, including using the NGX.I don't run any "outside" programs when running the sim. The only time I've windowedout is to look at a flight plan when sitting on the ground.Once I grab that, I'm back to full screen.

So, why are some Alt tabing when you can use the menu or Alt enter. Sorry, not being flippent, but why Alt Tab ?

Actually that was my fault I shoulda have been more clear on that. What I meant was any form of alt tab-enter out to the desktop. It not about the keystroke you use. Its about whether your multi-tasking in Fullscreen and then hoping back and forth to the desktop while in flight.

"BOTH" (short enough, and informative enough answer for you ? )

I run FSX in fullscreen (theoreticaly it is windowed mode but it looks like fullscreen cause you don't see the menue bar and the boarders of that window) and on the other screen I run FSrealWX, ACARS, Firefox, IVap and The Eye. Works very well.