Hi Atul_saini123,
So I checked your link and all seems correct on my computer.
At the bottom of the link you provided there is "see also" section, about activation / deactivation.
I did not deactivated my licenses before my window re-install, and if now I go to Flash Builder -> Help , desactivation button is greyed out. Could it be the source of my problem that I used my licenses on two computer and did not deactivated them ?
If yes, how could I deactivate thoses products ? I searched on my profile but I can't find a way to do it.