I've searched all over the interwebs but can't find an answer to this.
I have dual monitors, I'm playing CoD4 on my primary (not that primary or secondary matter), I have say MSN open on my secondary.
Now... While ingame I cannot alt tab (or any other similar function) to my secondary monitor WITHOUT MINIMISING COD4. I'm 99% sure that it IS possible to switch to the other monitor without minimising aforementioned game. This is due to a friend being able to do it with no troubles at all (don't give me any nonsense about it not being possible, i've seen it for myself).
Well, my understanding is that any game that uses DirectX means when that window loses focus (as in you switch to MSN from the game), it automatically unloads the game from your graphics card's memory. That is why the game minimises, as the alternative is crashing, and then takes a few seconds to reload the game into the GPU's memory - hence the blank screen when you initially flick back to it.
In my experience, no modern game can keep itself alive and running when you remove focus from the window. However, as you've stated you don't want any nonsense about it not being possible I guess you know better than I do!!
If your mate has a setup that doesn't unload a game when it loses focus, please post up the PCs spec and which games it works on as I'm interested in how he's done this.
He's recently upgraded his PC, I've just bought his second monitor off him so I don't think we ever 'tested' it on his new setup. His old PC would have been brand new 3 years ago (CPU, GPU), can't tell you the specifics off the top of my head but I do not believe they are relevant in this case.
This just seems to be a phenomenon, but since we're talking about PC's this phenomenon must be in some way explainable.
P.S. Thankyou for not saying it is impossible, at the time my friend and I didn't know any better... I remember saying something like, "just alt tab to the other window (monitor)", he did it, it worked, he later made a bind for it on his keyboard. We didn't have any reason to think it was anything out of the normal at the time
I'm sure there's 1 or 2 people out there who can explain this, whether or not they're going to stumble on this page is another thing though...