So my Mint setup (Mint 17 on a Lenovo Yoga 13) was working perfectly fine earlier this morning. However, I pressed Ctrl+Alt+PgDn while trying to change between workspaces and it turned the entire screen into a terminal window (similar to the one seen when hitting Alt+F2 at the login screen). I logged in using my information, realized I just needed to reboot, and then did so. However, when I logged back in, my entire desktop was reset to default settings and I couldn't change any of my desktop settings at all. It turns out my home folder's permissions had been changed from my account to root, so I changed them back to how they originally were and rebooted. The issue still persisted however, so I honestly have no idea what to do at this point. Now every time I log in my desktop resets itself as if Mint was just installed. My applications work fine however. I may be missing something really obvious so if anyone has any thoughts it'd be much appreciated.
Did you change your home directory permissions recursively?
i.e. (replace 'user1' with your user name)
chown -R user1:user1 /home/user1/
Note: If you did not already know, always be extremely careful when running chown recursively, as it can be very tricky to undo if you change permissions for everything in a directory with a variety of file/directory ownerships set for various files and directories within it.