How can I install the "third party" software option after I've skipped it in the installer? [duplicate]

Solution 1:

Open a terminal on the Dash and type:

sudo apt-get install ubuntu-restricted-extras

Enter your password and all third-party programs that you need to be installed. With this packages you will get also some extras like Microsoft fonts.

If you need proprietary drivers, go to System Settings -> Software & Updates and choose the hive "Additional drivers".