04.4LTS VERSION

My system works fine but yesterday I just reinstalled Wine and in the process of installing it started responding slowly as I am unaware of that situation,started pressing ESC and alt+ctrl+del keys continuously and after a while it started working fine. Then I restarted it.

And when I did the restart, after I successfully logged in, a terminal window pops up instead of the desktop. What should I do to start my PC normally?

The problem persists after I shutdown and restart as well.
The commands are working fine when I typed in the terminal but I can't get my home screen and access it just like other PC.

I am new to Ubuntu!!!

Please provide step by step procedure.

Thanks in advance!!!