I tried to uninstall Nvidia drivers and rebooted my PC to kernel 3.5.0-2-generic #2~precise1-Ubuntu, now my PC is using nouveau drivers and I can logon to my session perfectly.
I tried to uninstall Nvidia drivers and rebooted my PC to kernel 3.5.0-2-generic #2~precise1-Ubuntu, now my PC is using nouveau drivers and I can logon to my session perfectly.