I had a program installing on Ubuntu called 'ubuntu-restricted-extras' and then my system shutdown because of powerfailure, I restarted and then tried the installation again and it comes up with a message saying "Previous Installation hasn't been completed." and then tells me that I have to repair this before I can install or remove any further software. What do I need to do to fix this?
Open a terminal by hitting Ctrl+Alt+T, and type the following:
(Enter your password when prompted.)
This will start configuring packages (applications) that were about to be installed (unpacked) but not configured. Once this is finished, open up the Ubuntu Software Center and try to install the program again (if it's not already installed).
If the above does not fix your problem, type the following in the terminal:
This will attempt to download and install packages that are needed to run programs.