Do you want to enable the command ‘Open as Administrator’ to the context menu in Ubuntu 12.04. When this feature is enabled, you should be able to right-click any file or folder in nautilus and open it as an administrator or root. This will come in handy especially for new users who want to edit or modify files or folders owned by the root user or administrator.
To get started, press Ctrl + Alt + T on your keyboard to open Terminal. When it opens, run the commands below to download it.
wget http://www.liberiangeek.net/blog/tools/libnautilus-gksu.so
Next, copy the file to the folder using the following command.
sudo cp libnautilus-gksu.so /usr/lib/nautilus/extensions-3.0/
Restart your computer or use "nautilus -q" to view the changes.