Regarding the Arma 3 free weekend.

its so far down that I didn't even noticed it, well now I have no chance to play it. I need between 8-10 hours to download it i think.

Did you restart Steam? Usually when there are free weekends game adds to your library after you restart Steam.

not doomed to

Reinstall Windows, it usually helps everybody xD

would you send a screenshot of the end of your libary? Maybe we can see the game for you xD Otherwise, did you try to logout and in? you only restarted steam that usualy doesn't really help

It is only free for another 6 hours or so. Frankly by the time you download it, install it, and figure out wtf you are doing, time will be up. If you just wanted to play to see if you'd like it, there are tons and tons of good videos on youtube.

Just go here and click on "Play Game" to add to your inventory. This isn't a 'play for a limited time' game, it is a 'keep forever' game. As long as it is in your inventory, it is yours.

Just download at a later date. But add it A.S.A.P.

EDIT: Sorry, I assumed it was the other ARMA game, just noticed ARMA III. :/