Compliant 18.04.

logic would dictate one would upgrade

Compliant to what?

Nobody forces you to use Ubuntu 18.04. You have the free choice between a number of supported releases, currently 16.04, 18.04 and 19.10, eventually also 14.04 ESM and the upcoming development version (20.04, to be officially release in April).

What happens if you try viewing clips from YouTube, and which browser are you using?

New users in Ubuntu will notice that for some reason, a lot of audio
and video codecs aren't available immediately in Ubuntu, unlike Windows
or Mac. This happens basically for legal and technical reasons. Ubuntu
excludes these codecs because these video files and other media formats
are copy-right protected, so you can't just add these protected
technology to your operating systems and programs without agreeing to
their licensing terms and conditions. The error is basically is the
following...
How do we play .mp4 and .mov files on 18.04...?

On Sat, 2020-02-22 at 11:10 +0000, Manfred Hampl wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
>     Status: Open => Needs information
>
> Manfred Hampl requested more information:
> Compliant to what?
>
> Nobody forces you to use Ubuntu 18.04. You have the free choice
> between
> a number of supported releases, currently 16.04, 18.04 and 19.10,
> eventually also 14.04 ESM and the upcoming development version
> (20.04,
> to be officially release in April).
>
> What happens if you try viewing clips from YouTube, and which browser
> are you using?
>

Issue the command

sudo apt install ubuntu-restricted-extras

Remark: There is a question asked by the Ubuntu installer, whether these packages should be installed from the beginning. If you haven't selected this at install time, then you can add the packages in question by the command given above.

Don't blame Ubuntu for obeying licensing rules, even if other operating systems might be a bit negligent with that matter.

Installing Ubuntu alongside other O/S is easy...
however "Un-installing" the partition is not easy..
Therfore I have been trying my various software and apps
from the "try" ubuntu dvd. Your answer seems to imply that 18.04
has to be "installed" not "tried" to know what works and what
doesn't work..correct?

On Sat, 2020-02-22 at 19:28 +0000, Manfred Hampl wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
>     Status: Open => Answered
>
> Manfred Hampl proposed the following answer:
> Issue the command
>
> sudo apt install ubuntu-restricted-extras
>
> Remark: There is a question asked by the Ubuntu installer, whether
> these
> packages should be installed from the beginning. If you haven't
> selected
> this at install time, then you can add the packages in question by
> the
> command given above.
>
> Don't blame Ubuntu for obeying licensing rules, even if other
> operating
> systems might be a bit negligent with that matter.
>

Un-installing the partition is easy, in Windows, delete the Ubuntu partitions using Windows disk manager, resize the Windows disk into the new freed space. You can then reinstate the Windows boot loader to boot Windows as you have wiped the configuration for GRUB.......

Your questions
"Un-installing" the partition is not easy."
"Ubuntu has to be "installed" not "tried" to know what works and what doesn't work..correct?"

Ubuntu is an Operating System, and not a software program that can easily be installed and uninstalled.
Installing an Operating System requires a disk partition dedicated for that operating system (or eventually additional virtualization software to installit inside another operating system).
"Uninstalling" the Operating System means deleting (or emptying) the partition that is dedicated for taht operating system. This is the same for all OSes (you can't "uninstall Windows", or Android, or iOS or macOS either).

The Ubuntu installer medium (either DVD or USB-stick) allows to use the Ubuntu operating system without installing it in a "Try Ubuntu wihout installing" mode. You can use it this way to test if it works on your hardware, whether you like the look and feel, etc., but you have to be aware that there are limitations when using Ubuntu this way.

If you tell more details about what you want to achieve, we might be able to help further.

OK...I am trying to achieve/play videos (that work fine on 16.04).
Files like .mp4, .mov, etc.
When file selected error message appears: “Unable to play the file”
“MPEG-4 AAC decoder, H.264(Main Profile) decoder are required to play
the file but not installed” Tried to install packages using sudo
commands suggested. Does  Not Work. On the error message it says “Find
Software” In the software store “H.264 (High Profile) decoder Not
found”. No install button Just “visit Website” which does not work.
How can I play these videos…?
thanks

On Sun, 2020-02-23 at 10:04 +0000, Manfred Hampl wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
> Manfred Hampl proposed the following answer:
> Your questions
> "Un-installing" the partition is not easy."
> "Ubuntu has to be "installed" not "tried" to know what works and what
> doesn't work..correct?"
>
> Ubuntu is an Operating System, and not a software program that can
> easily be installed and uninstalled.
> Installing an Operating System requires a disk partition dedicated
> for that operating system (or eventually additional virtualization
> software to installit inside another operating system).
> "Uninstalling" the Operating System means deleting (or emptying) the
> partition that is dedicated for taht operating system. This is the
> same for all OSes (you can't "uninstall Windows", or Android, or iOS
> or macOS either).
>
> The Ubuntu installer medium (either DVD or USB-stick) allows to use
> the
> Ubuntu operating system without installing it in a "Try Ubuntu wihout
> installing" mode. You can use it this way to test if it works on your
> hardware, whether you like the look and feel, etc., but you have to
> be
> aware that there are limitations when using Ubuntu this way.
>
> If you tell more details about what you want to achieve, we might be
> able to help further.
>

What do you mean with "Does Not Work."?
Did the command fail with an error message, or did the command end without error, but did not have a positive effect on playing videos?

Maybe you need additional packages, execute the command

sudo apt install libdvdnav4 libdvdread4 gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly libdvd-pkg

and try the video again.

By the way, if Ubuntu 16.04 worked well, why did you then upgrade to 18.04?

THOSE COMMANDS DID NOT WORK...
(as mentioned in my email).

On Sun, 2020-02-23 at 21:09 +0000, Manfred Hampl wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
>     Status: Open => Answered
>
> Manfred Hampl proposed the following answer:
> What do you mean with "Does  Not Work."?
> Did the command fail with an error message, or did the command end
> without error, but did not have a positive effect on playing videos?
>
> Maybe you need additional packages, execute the command
>
> sudo apt install libdvdnav4 libdvdread4 gstreamer1.0-plugins-bad
> gstreamer1.0-plugins-ugly libdvd-pkg
>
> and try the video again.
>
> By the way, if Ubuntu 16.04 worked well, why did you then upgrade to
> 18.04?
>

Did not work in what sense?

DID NOT PLAY THE VIDEO.
error message when executing the command..."Package Not Found"

On Sun, Feb 23, 2020, 3:23 PM Manfred Hampl <
<email address hidden>> wrote:

> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
> Status: Open => Needs information
>
> Manfred Hampl requested more information:
> Did not work in what sense?
>
> --
> To answer this request for more information, you can either reply to
> this email or enter your reply at the following page:
> https://answers.launchpad.net/ubuntu/+question/688919
>
> You received this question notification because you asked the question.
>

Please provide the full output that you receive when you execute that command.

Install VLC and use that. It'll play most things on your drive.

VLC does NOT work properly!
thanks
SOLVED!

On Sun, 2020-02-23 at 21:42 +0000, actionparsnip wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
>     Status: Needs information => Answered
>
> actionparsnip proposed the following answer:
> Install VLC and use that. It'll play most things on your drive.
>

In my opinion DO NOT USE Ubuntu 18.04 IF you want to view movies , .mov, .mp4, .pdf files or document viewer or have a workable copy of VLC. However if you want a compliant – with licensing agreements - O/S with Less functionality than older versions install it!
Solved!

Works fine for me....

great to hear that.

On Mon, 2020-02-24 at 19:17 +0000, actionparsnip wrote:
> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
> actionparsnip posted a new comment:
> Works fine for me....
>

I future if you actually explain your issue rather than some emotional crap that helps nobody, most of all you, then we may be able to help. It adds no value.

Thank you for the clarification.

On Mon, Feb 24, 2020, 5:08 PM actionparsnip <
<email address hidden>> wrote:

> Your question #688919 on Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+question/688919
>
> actionparsnip posted a new comment:
> I future if you actually explain your issue rather than some emotional
> crap that helps nobody, most of all you, then we may be able to help. It
> adds no value.
>
> --
> You received this question notification because you asked the question.
>