I did something in CompizConfig Manager and the launcher and other bars was gone!
- I tried using the set background from right click menu and checked if it was a driver problem, but it was not.
- I also tried keyboard shortcuts for terminal etc. but none worked.
- I switched my PC off and logged in with standard user which doesn't have a password and it worked completely.
So I went back to the account with problem (admin) and made it a standard user and the other user an admin but I forgot to set a password for the other account.
Now I can't do anything in the other account because it requires admin password and my not working admin's user password doesn't work, and the other user which I made admin doesn't have a password so I can't do anything like access hard drive to save my user files to windows partition, delete account, delete compiz etc.
Best Answer
Your original problem could have been solved by opening a terminal and issuing the command:
It's likely that your easiest course of action at this point is to:
Boot from live installation media (CD/DVD/USB) Select "Try Ubuntu without making changes to your computer"
Mount the drive that contains your user files, back them up by copying them to the aforementioned windows partition or other available media as desired.
Reinstall.
In future, I highly recommend backing up regularly and prior to making any changes to your system.