Totem won't play dvds

You need to add the Medibuntu Repository and then tha package libdvdcss2. Look at https://help.ubuntu.com/community/Medibuntu and scroll down to "Playing Encrypted DVDs"

Or you can just run:

sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update; sudo apt-get install libdvdcss2

and you will be fine

Thank you very much actionparsnip, for the first time my use of a terminal window was successful and I've been a half and half user between Linux and Windows for about a year now. I must admit I am very timid with Linux anyway.

Thank you very much actionparsnip, for the first time my use of a terminal window was successful and I've been a half and half user between Linux and Windows for about a year now. I must admit I am very timid with Linux anyway.

You'll learn, just as you learned other OSes

for actionparsnip;

Your solution worked for me, but I find I have to repeat the proceedure every time I start the computer. Why would the information not be retained?

Which bit are you repeating?

That which you posted earlier, [sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update; sudo apt-get install libdvdcss2].
The VLC player works ok, but Totem gives me the [Totem cannot play this type of media (DVD) because it does not have the appropriate plugins to be able to read from the disc.] DVD source error?
Any ideas what might be going on?

I'd use VLC then