question how do you add meta description to the login forum and lost password section

 

that did not answer my question i now that basically there is no way of doing this because when you hit the log in it bring it up like a popup

Add it manually and the "Page Address" is "login" and "lostpassword". Not sure what good that'll do to you, but it'll give Google some meta's on those pages, as Google will obviously not see them as popups.