Stuck on login screen LENOVO ideapad Y700 with Geforce GTX960 on ubuntu

Hey guys i got a big problem, i have try every thing that i found in inteet and nothing helps me.

I just by lenovo ideapad Y700 with geforce gtx 960, and my OP is UBUNTU 14.04.4

After that i follow steps of this post of Jempa333 http://ubuntuforums.org/showthread.php?t=2263316,
i'm stuck on login screen and can't login to desktop. always when i'm enter user and password in login screen, i'm retuing to the same login screen and can't enter to the desktop.
what can be a reason of this? Any body please help!
thank's for advice