I downloaded this program http://shutter-project.org/ from that site and followed instructions how to install it.
when I typed
sudo apt-get install shutter
I had message which showed me which files need to be downloaded and installed, selected "yes" and after couple of seconds I noticed that terminal is deleting my files.
I thought they are unnecessary but that all of the sudden things started to disappear on my desktop and when I had nothing except wallpaper. I pressed reboot button.
When my PC booted again I only saw login screen and couldn't login in any of sessions I had.
Can you tell me what happened? I'm on Windows now.