Yes, it crashed, i run the reg for uninstalling it, and apparently it's not crashing any more.
I guess that was the problem.

If it happens again ill report updates

Jimmy, u are right, im trying this right now, will update soon

Switching back to 1.38 seem to have made it working, but it might be the same thing that happened when i actually installed the update and it was working, but just for a while.

If the crash happens again i'll update this request and let you know.

Btw im also fowarding this solution in the forum

At the moment im switching back from 1.36 to stable branch.

Ill try to start arma without touching whichever tweak is actually running, and then if it crashes again, ill try that .reg for disabling it and see what happens

Yes, it might be, im not sure it's running right now but i remember this page, i have seen it before, and i tend to tweak a lot my pc

5. why did u link me this tread on the steam forums? It's a different game and i never used "games for windows live" in my life.

Arma3 doesnt use GFWL and i didn't install it in the last 12 hours.
Yesterday night it was working perfectly fine.

I have heard people in forums complaining about a recent A3 update. Maybe is update related. Cant say if my a3 updated tonight btw, i was sleeping, and left the pc running with steam open

More infos for you:

http://forums.bistudio.com/showthread.php?188220-Arma-3-APPCRASH-in-kernelbase-dll-after-changing-monitor

an user in this thread gave me a password for the 1.36 steam version beta subscription.

I just installed it and it works.

So it's a problem with the last patch

1. i didn't install any driver
2. i managed to find another monitor which is exactly the same as the 1st one, the problem is still here, so i guess it was a coincidence, it's not monitor related
3. i am not running any mod at the moment, the crash is still here.
4. the lines inside my CFG, like i have wrote in the initial post, have been corrected both times accordingly to the specs of the monitor used.

I even tried removing the cfg file completely, arma3 doesnt reach a state in which it creates a new one, it crashes well before it.