Step 4: Change the root password.

In order to access the add/remove software menu you will need to enter the root (aka the administrator) password on the system. Since Acer doesn't tell you what the original root password is, you need to change it to something you can remember.

• Open a terminal window by right clicking on the desktop and select System > Terminal. 
• Type "Sudo –su" at the command prompt amd hit Enter.
• Type "passwd" and hit Enter.
• Enter a new root password. Your password cannot be a dictionary word, but rather a combination of letters and numbers. Press Enter.
• Retype your password. Your new password is set.