Can i GA, games that already i won in another GA?

if you win something, you must activate it on your account. don't enter for games you don't want.

Then don't enter. Regifting games you've won is a scumbag move.

Can't stress enough: If you don't want the game, don't enter and lower chances of someone who might actually want it.

If you activated key and bought another copy you can. You cannot regift won key.