Recently, I tried to upgrade the ubuntu version 15.04 to 15.10. I think I couldn't complete the installation completely. Now the problem is I'm not able to login from my login screen which showing as 15.04. When the password is given, the screen will appear as it is without any desktop icons and sometimes no cursor. But i could do a restart or shut down from the screen if I haven't provide a login password. I tried even terminal also but there shows login incorrect when the password is given.Also there it is showing as ubuntu 15.10
I have a DELL vostro 3446 with Nvidia drivers GT 820M. Once there was a problem of continuous restarting and got solved by using an alternate driver.
How to sole this issue? Anybody can help me? I'm really afraid of updating my system now. every time it ends up with such kind of issues.