How do I restore default settings and configuration, but keep local data, installed apps, and PPAs?

I'm fairly new to Ubuntu and while messing around with different things and trying out some shells, I've managed to mess my system up. Specifically I really messed up my GNOME session and can't get it to run really at all.

Is there a way to backup my apps but reinstall or just "restore" Ubuntu to its original condition? I had tons of updates installed, downloaded and setup my machine for Android development, and a few other things with a very slow internet connection.

Solution 1:

Open a terminal and try this command:

rm -r ~/.config/ ~/.cache/

and relogin. In a perfect world, this would restore a stock environment without any data loss. The world is good enough that it may work for you. However, not all software is standards compliant, so... if your login is still borked, backup everything and run:

rm -rf ~/.[^.]*

This will delete configuration for all applications. It will also delete some user information, such as your browser login information, your email credentials, save game files, etc.