I can not play battlefield3 because not activate although i have account

Hey there, 

Please try the troubleshooting steps below and let us know if that helps:

Delete EA License Files:

• Make sure the EA app is closed.
• Press the Windows key and "R" at the same time.
• Type or copy and paste "%ProgramData%\Electronic Arts\EA Services" (without the quotes) into the new Window > ENTER
• Enable View Hidden Files and Folders
• Delete all files in the "License" folder.

Clear your temp files:

• Press the Windows key and "R" at the same time
• Into the new window, type or copy & paste: "%temp%" (Without the quotes.) > hit "ENTER"
• Your Windows Explorer should have brought you to the "C:\Users\>your user name<\AppData\Local\Temp" folder. > Delete all files and folders in it.
• (If some files or folders can't be deleted, reboot and try again.)

Unfortunately did not work :(

I'm sorry to hear the steps didn't fix that for you. 

Just to confirm, which platform are you using to launch the game?

The same problem, using steam startup, is there any other way to solve it

Usually, deleting the license folder is the main step to fix this problem. However, some other players have reported that a clean boot has also helped with this: 

How to clean or safe boot your computer