How do I reset everything in regards to my network connection?

I've been trying for weeks to try and get my wireless adapter (Atheros) to play nicely with a PEAP network at my University. It connected to just about anything, except for the one here. After trying desperately for hours trying different commands and workarounds to get it to work correctly (most solutions specifically made for my adapter, others for Atheros in general), my adapter seems to have become useless.

I can't connect to anything - wireless or LAN, and it's kind of a problem. gnome-control-panel shows the word "unmanaged" under the adapter name while under network settings. The wireless combobox (for finding a network) only shows "other" and selecting "other" doesn't seem to do anything.

Is there a way for me to undo everything in regards to my network? I don't want to have to reinstall Ubuntu - that would be a huge pain. I'm also not sure what could be causing the problem. Is there some way for me to clear the drivers I've installed for the adapters and the config settings for them as well to get it working again?

For Reference:

• Ubuntu 12.04 LTS x64
• Same adapter still works fine (even for PEAP) on Windows 7/8 x64
• Atheros AR5BWB222 Wireless Network Adapter and Atheros AR8151 PCI-E Gigabit Ethernet Controller (NDIS 6.20) [ per Windows Device Manager Report ]
• I've tried WICD with no success at all.

If you want to remove every configuration about your network, you can reinstall the packages that has anything to do with whatever you have touched, examples:

• If you only touched the /etc/network* files, the easy way to go is purging the packages and reinstall them again (you should download separatelly the package):

  dpkg -S /etc/network
  avahi-autoipd, avahi-daemon, netbase, ntpdate, wireless-tools, wpasupplicant, ifupdown, clamav-freshclam: /etc/network
  sudo dpkg --purge packages
  sudo dpkg -i packages
  

• If what you touched was more superficial, dpkg-reconfigure is your friend:

  sudo dpkg-reconfigure packages
  

• If you want a sure kill solution, reinstall from scratch :(.

Of course, if you had a list of every action you did, this would be more ease as going backwards in a video, reversing every change.

You can reset everything pertaining to your networks, just press Ctrl+Alt+T and type in:

sudo service networking restart

Continue to restart your machine, and it will reconfigure the default settings upon restart.

However, there are issues whereby Ubuntu writes "Booting Up without full network config"...a second restart will do the trick

See also:

• How to restart the networking service?