how can I reset to default, or find out how my software sources were originally set when I upgraded to 9.10?

Why do you think you have untrusted software running? What's happening?

Everything in the Ubuntu repositories should be clean (ie. no malware). You might have dodgy software if you added a suspicious repository in the "Other Software" tab or installed a suspicious application using a .deb file.

You shouldn't need to reset your repositories to defaults. Removing repositories after you've installed software from them is usually a bad idea because you won't get the updates.

go to system - administration - soft ware sources there you will find a "revert" button.

David
in TN

All software sources on the "Ubuntu Software" tab are repositories hosted by Ubuntu, and there shouldn't be trust issues with them. If you only have trusted Ubuntu sources enabled and you still get a warning about unauthenticated software sources or something similar, try refreshing package information for example by clicking "Reload" in Synaptic Package Manager. (If you change your software sources, you should also be prompted for refreshing package information, so that should also do it.)

As for software sources on the "Other Software" tab, the Canonical Partner repository is an official Canonical software source and shouldn't cause any trust issues. The entry for that repository is "http://archive.canonical.com/ubuntu karmic partner". There might also be an entry for an Ubuntu install/live CD.

If you have other sources than the Canonical Partner repository and an Ubuntu CD listed on the "Other Software" tab, those may be ones you've added yourself.

The defaults for the "Updates" tab are to enable security updates and recommended updates but to disable pre-released and unsupported updates. Any of these update settings shouldn't cause any trust issues, however, since all updates sources configurable on that tab are trusted Ubuntu sources.

The revert button doesn't actually revert your configuration to default values but just reverts any changes you've made since opening the Software Sources configuration.

If you still have issues, can you give a better description of the problem you're facing, the exact error message you get (if any), etc.?

When I "run" update manager this happens:
several updates show available, I choose to install them all
a pop up screen says
"apply the following changes?"
This is your last opportunity to look through the list of marked changes before they are applied"
"Warning"
You are about to install software that can't be authenticated. Doing this could allow a malicious individual to damage or take control of your system"
then etc..etc..
Let me clarify the key to my issue is self inflicted!I made changes to the Other software tab and update tab and did not save a copy of what they were!!!
Under Ubuntu Software-only source code is unchecked, set to main server
Under Other Software http://archive.canonical.com/ubuntu karmic partner and http://archive.canonical.com/ubuntu karmic partner (source code) are only unchecked. Unsupported updates; Unsupported updates (source code); Medibuntu-Ubuntu 9.04 "jaunty jackalope" disabled on upgrade to karmic free non-free and Medibuntu (source)-Ubuntu 9.04 "jaunty jackalope" free non-free (source code) are checked. I believe this is here I have something set wrong.
Under Update tab: only pre-released updates and unsupported updates are unchecked.
I am very appreciative of your efforts and time!!!!

Looks like you had Medibuntu and it was disabled when you updated. After you re-enabled it, the key wasn't added so now you're having key errors.

Delete the repository entirely from Software Sources, then follow the instructions on this page in the "Adding the Repository" section.
https://help.ubuntu.com/community/Medibuntu

You can copy and paste their big long command into Terminal (Ctrl + Shift + V, or Edit > Paste to paste).

There are a few options I can think of that could cause such issues. Could you try and find out the following pieces of information and let us know?

1. How long has the issue persisted? Just for a day or two? Several days? Weeks? Do you remember doing something particular with your software sources just before the problem with updates appeared? Did the problem occur right after you enabled the Medibuntu repositories?

2. When you try to apply updates and the warning appears, can you try and open the details of the warning? It should allow you to view which packages the updater is unable to authenticate. Are all packages being updated suffering from this, or just specific packages?

3. Also, I've sometimes seen temporary package authentication problems even with official Ubuntu repositories, perhaps due to the package information refresh being interrupted or something. Those temporary problems have been solved by refreshing the package information. That's why I asked if you could try that. If you haven't done it yet, could you click the "Check" button in Update Manager to re-check for updates and try applying the updates again? Does that have any effect?

4. You mentioned that you believe there's something wrong with your "Other Software" settings. If the suggestions given above didn't help, have you tried temporarily unchecking the Medibuntu or other entries on the "Other Software" tab?

5. The keys used for authenticating packages are listed on the "Authentication" tab. You should have one entry for the Ubuntu Archive Automatic Signing Key and probably one for the Ubuntu CD Image Automatic Signing Key. Also, if you use other archives such as Medibuntu, there should probably be a separate key for that, too. Does it look like any keys are missing?

6. Judging by your previous message it looks like your Medibuntu software sources are for Ubuntu 9.04 and not for 9.10. Is this on purpose?

Ryan-here is a copy of my terminal session-it shows the original issue I was trying to correct when I made changes to software sources (see the failed to fetch portion)
paul@paul-desktop:~$ 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] password for paul:
--2010-01-11 20:10:51-- http://www.medibuntu.org/sources.list.d/karmic.list
Resolving www.medibuntu.org... 87.98.242.110
Connecting to www.medibuntu.org|87.98.242.110|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 272 [text/plain]
Saving to: `/etc/apt/sources.list.d/medibuntu.list'

100%[======================================>] 272 --.-K/s in 0s

2010-01-11 20:10:51 (18.6 MB/s) - `/etc/apt/sources.list.d/medibuntu.list' saved [272/272]

Hit http://archive.ubuntu.com karmic Release.gpg
Ign http://archive.ubuntu.com karmic/main Translation-en_US
Ign http://archive.ubuntu.com karmic/restricted Translation-en_US
Ign http://us.archive.ubuntu.com gutsy-backports Release.gpg
Ign http://us.archive.ubuntu.com gutsy-backports/main Translation-en_US
Ign http://us.archive.ubuntu.com gutsy-backports/restricted Translation-en_US
Ign http://archive.ubuntu.com karmic/universe Translation-en_US
Ign http://archive.ubuntu.com karmic/multiverse Translation-en_US
Hit http://archive.ubuntu.com karmic-updates Release.gpg
Ign http://archive.ubuntu.com karmic-updates/main Translation-en_US
Ign http://archive.ubuntu.com karmic-updates/restricted Translation-en_US
Ign http://archive.ubuntu.com karmic-updates/universe Translation-en_US
Ign http://archive.ubuntu.com karmic-updates/multiverse Translation-en_US
Hit http://archive.ubuntu.com karmic-security Release.gpg
Ign http://us.archive.ubuntu.com gutsy-backports/universe Translation-en_US
Ign http://us.archive.ubuntu.com gutsy-backports/multiverse Translation-en_US
Ign http://us.archive.ubuntu.com gutsy-backports Release
Get:1 http://packages.medibuntu.org karmic Release.gpg [197B]
Ign http://packages.medibuntu.org karmic/free Translation-en_US
Ign http://packages.medibuntu.org karmic/non-free Translation-en_US
Ign http://archive.ubuntu.com karmic-security/main Translation-en_US
Ign http://archive.ubuntu.com karmic-security/restricted Translation-en_US
Ign http://archive.ubuntu.com karmic-security/universe Translation-en_US
Ign http://archive.ubuntu.com karmic-security/multiverse Translation-en_US
Hit http://archive.ubuntu.com karmic Release
Hit http://archive.ubuntu.com karmic-updates Release
Ign http://us.archive.ubuntu.com gutsy-backports/main Packages
Get:2 http://packages.medibuntu.org karmic Release [9,237B]
Ign http://packages.medibuntu.org karmic Release
Ign http://us.archive.ubuntu.com gutsy-backports/restricted Packages
Ign http://us.archive.ubuntu.com gutsy-backports/universe Packages
Ign http://us.archive.ubuntu.com gutsy-backports/multiverse Packages
Ign http://us.archive.ubuntu.com gutsy-backports/main Sources
Hit http://archive.ubuntu.com karmic-security Release
Hit http://packages.medibuntu.org karmic/free Packages
Ign http://us.archive.ubuntu.com gutsy-backports/restricted Sources
Ign http://us.archive.ubuntu.com gutsy-backports/universe Sources
Ign http://us.archive.ubuntu.com gutsy-backports/multiverse Sources
Ign http://us.archive.ubuntu.com gutsy-backports/main Packages
Hit http://archive.ubuntu.com karmic/main Packages
Hit http://archive.ubuntu.com karmic/restricted Packages
Hit http://archive.ubuntu.com karmic/universe Packages
Ign http://us.archive.ubuntu.com gutsy-backports/restricted Packages
Ign http://us.archive.ubuntu.com gutsy-backports/universe Packages
Ign http://us.archive.ubuntu.com gutsy-backports/multiverse Packages
Hit http://packages.medibuntu.org karmic/non-free Packages
Hit http://archive.ubuntu.com karmic/multiverse Packages
Hit http://archive.ubuntu.com karmic-updates/main Packages
Hit http://archive.ubuntu.com karmic-updates/restricted Packages
Hit http://archive.ubuntu.com karmic-updates/universe Packages
Hit http://archive.ubuntu.com karmic-updates/multiverse Packages
Ign http://us.archive.ubuntu.com gutsy-backports/main Sources
Ign http://us.archive.ubuntu.com gutsy-backports/restricted Sources
Ign http://us.archive.ubuntu.com gutsy-backports/universe Sources
Ign http://us.archive.ubuntu.com gutsy-backports/multiverse Sources
Hit http://archive.ubuntu.com karmic-security/main Packages
Hit http://archive.ubuntu.com karmic-security/restricted Packages
Hit http://archive.ubuntu.com karmic-security/universe Packages
Hit http://archive.ubuntu.com karmic-security/multiverse Packages
Err http://us.archive.ubuntu.com gutsy-backports/main Packages
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/restricted Packages
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/universe Packages
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/multiverse Packages
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/main Sources
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/restricted Sources
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/universe Sources
  404 Not Found [IP: 91.189.88.46 80]
Err http://us.archive.ubuntu.com gutsy-backports/multiverse Sources
  404 Not Found [IP: 91.189.88.46 80]
Fetched 198B in 1s (164B/s)
W: GPG error: http://packages.medibuntu.org karmic Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/main/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/restricted/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/universe/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/multiverse/binary-i386/Packages.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/main/source/Sources.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/restricted/source/Sources.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/universe/source/Sources.gz 404 Not Found [IP: 91.189.88.46 80]

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/gutsy-backports/multiverse/source/Sources.gz 404 Not Found [IP: 91.189.88.46 80]

E: Some index files failed to download, they have been ignored, or old ones used instead.
paul@paul-desktop:~$ sudo apt-get --yes install app-install-data-medibuntu apport-hooks-medibuntu
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  app-install-data-medibuntu apport-hooks-medibuntu
0 upgraded, 2 newly installed, 0 to remove and 2 not upgraded.
Need to get 17.1kB of archives.
After this operation, 176kB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  app-install-data-medibuntu apport-hooks-medibuntu
E: There are problems and -y was used without --force-yes
paul@paul-desktop:~$
Unfortunately, after trying all of this-I am right back to the warning screen when I try to run an update manager

Mike-SORRY FOR THE CAPS
1. How long has the issue persisted? Just for a day or two? Several days-YES @ 5-6 DAYS NOW? Weeks? Do you remember doing something particular with your software sources just before the problem with updates appeared-YES-UPGRADE FROM 9.04 TO 9,10 AND GOT THE FAILED TO FETCH WARNINGS THAT YOU CAN SEE IN MY TERMINAL SESSION ABOVE? Did the problem occur right after you enabled the Medibuntu repositories-I DO NOT KNOW THE ANSWER TO THAT QUESTION-NOT THAT UBUNTU SMART YET?

2. When you try to apply updates and the warning appears, can you try and open the details of the warning? It should allow you to view which packages the updater is unable to authenticate.-YES HERE YOU GO
libavcodec-extra-52 (version 4:0.5+svn20090706-2ubuntu3) will be upgraded to version 4:0.5+svn20090706-2ubuntu3+medibuntu1
libavcodec-unstripped-52 (version 4:0.5+svn20090706-2ubuntu3) will be upgraded to version 4:0.5+svn20090706-2ubuntu3+medibuntu1
apport-hooks-medibuntu (version 1medibuntu1) will be installed
libamrnb3 (version 7.0.0.2-0.1medibuntu1) will be installed
libamrwb3 (version 7.0.0.3-0.0medibuntu1) will be installed
 Are all packages being updated suffering from this, or just specific packages? I DO NOT KNOW THE ANSWER TO THIS QUESTION

3. Also, I've sometimes seen temporary package authentication problems even with official Ubuntu repositories, perhaps due to the package information refresh being interrupted or something. Those temporary problems have been solved by refreshing the package information. That's why I asked if you could try that. If you haven't done it yet, could you click the "Check" button in Update Manager to re-check for updates and try applying the updates again? Does that have any effect? i HAVE BEEN HITTING CHECK AND DOING IT FROM UPDATE MANAGER AND TERMINAL AND GETTING SAME RESULTS

4. You mentioned that you believe there's something wrong with your "Other Software" settings. If the suggestions given above didn't help, have you tried temporarily unchecking the Medibuntu or other entries on the "Other Software" tab? YES, THAT ELIMINATES THE FAILED TO FETCH WARNING AND THEN ADDS THE UPDATES THAT CREATE THE WARNING OF AUTHENTICITY.

5. The keys used for authenticating packages are listed on the "Authentication" tab. You should have one entry for the Ubuntu Archive Automatic Signing Key and probably one for the Ubuntu CD Image Automatic Signing Key. Also, if you use other archives such as Medibuntu, there should probably be a separate key for that, too. Does it look like any keys are missing? THOSE ARE THE ONLY TWO KEYS THAT APPEAR.

6. Judging by your previous message it looks like your Medibuntu software sources are for Ubuntu 9.04 and not for 9.10. Is this on purpose? NO, AND IF THIS IS THE ROOT OF MY ISSUE PLEASE HELP EXPLAIN HOW I CAN RESOLVE IT!

AGAIN-I apologize for the caps-just trying to show my answers!

You have entries for Gutsy, which is no longer supported. That's why you're getting failed entries for it. There's actually no problem with the Medibuntu repository - the first update after adding it gives the GPG error, but the package it installs stops that. The error you're getting in subsequent updates are from Gutsy alone.

Can you open your /etc/apt/sources.list file with gedit (text editor), then paste it to pastebin.com and post the link here?

I do not know how to do what you have requested????

maybe this is it???

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://archive.ubuntu.com/ubuntu/ karmic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://archive.ubuntu.com/ubuntu/ karmic universe
deb http://archive.ubuntu.com/ubuntu/ karmic-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu/ karmic multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository. This software is not part of Ubuntu, but is
## offered by Canonical and the respective vendors as a service to Ubuntu
## users.
# deb http://archive.canonical.com/ubuntu karmic partner
# deb-src http://archive.canonical.com/ubuntu karmic partner

deb http://archive.ubuntu.com/ubuntu/ karmic-security main restricted
deb http://archive.ubuntu.com/ubuntu/ karmic-security universe
deb http://archive.ubuntu.com/ubuntu/ karmic-security multiverse

OK, you'll need to edit your sources.list file.

Go to Applications > Accessories > Terminal. Type in: sudo nano /etc/apt/sources.list # When it asks for your password, type it in - you won't see anything appear on the screen. In the editor, press the down arrow key until you get to the two lines with gutsy in them. Replace gutsy with karmic, so it reads karmic-backports, then put a # at the start of those two lines to comment them.

Press Ctrl + O then Enter to save your changes, then Ctrl + X to quit.

Then reload your packages and see what happens. If you still get errors you will need to install app-install-data-medibuntu and apport-hooks-medibuntu through Synaptic Package Manager, then reload again and you should be good.

when I typed your first line (sudo nano...etc.. and then hit enter and typed in my password and then hit enter again this came up:

  GNU nano 2.0.9 File: /etc/apt/sources.list

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://archive.ubuntu.com/ubuntu/ karmic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://archive.ubuntu.com/ubuntu/ karmic universe
deb http://archive.ubuntu.com/ubuntu/ karmic-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu/ karmic multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository. This software is not part of Ubuntu, but is
## offered by Canonical and the respective vendors as a service to Ubuntu
## users.
# deb http://archive.canonical.com/ubuntu karmic partner
# deb-src http://archive.canonical.com/ubuntu karmic partner

deb http://archive.ubuntu.com/ubuntu/ karmic-security main restricted
deb http://archive.ubuntu.com/ubuntu/ karmic-security universe
deb http://archive.ubuntu.com/ubuntu/ karmic-security multiverse

I changed the two lines from Gutsy to karmic and added ONE # at the begining of each line. I will restart and run check for updates now!

ran update check
pop up says

An error Occurred
The following details were provided:

W: GPG error: http://packages.medibuntu.org karmic Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783

going to try second recomendation

did this:
install app-install-data-medibuntu and apport-hooks-medibuntu through Synaptic Package Manager, then reload again and you should be good.
same W:GPG error popped up again, clicked ok-then it offered a few updates that I installed. Not getting the failed to fetch anymore, but still getting same W:GPG error???? Clearly-you have guided me through some progress here, Ryan! Many thanks-could I ask for any last recomendations?

The problem seems to be that for some reason the authentication key for the Medibuntu repositories is missing. Ubuntu uses those keys (listed in Software Sources -> Authentication) to verify the authenticity of packages it's about to install, and for some reason it's missing from your system.

When you earlier removed and re-setup the Medibuntu software sources as Ryan instructed, the "sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring" part of the command should have installed the Medibuntu authentication key for you. Either that didn't work for some reason, or there's some other reason the key isn't working.

Could you try installing the authentication keys once more by running the following command? Please include a copy of the output of the command here as well.

sudo apt-get --yes --allow-unauthenticated install medibuntu-keyring

Also, could you check if the file /usr/share/keyrings/medibuntu-keyring.pgp exists on your system?

Hi Mike,

here is the outpu from terminal::
paul@paul-desktop:~$ sudo apt-get --yes --allow-unauthenticated install medibuntu-keyring
[sudo] password for paul:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  medibuntu-keyring
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 3,448B of archives.
After this operation, 49.2kB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  medibuntu-keyring
Authentication warning overridden.
Get:1 http://packages.medibuntu.org karmic/free medibuntu-keyring 2008.04.20 [3,448B]
Fetched 3,448B in 0s (4,122B/s)
Selecting previously deselected package medibuntu-keyring.
(Reading database ... 180076 files and directories currently installed.)
Unpacking medibuntu-keyring (from .../medibuntu-keyring_2008.04.20_all.deb) ...
Setting up medibuntu-keyring (2008.04.20) ...
OK

paul@paul-desktop:~$

yes, there is the file /usr/share/keyrings/medibuntu-keyring.pgp

I am going to restart and try updates again

I restarted, checked for updates-no errors and it said my most recent update was less than one hour ago! I am going to call this PROBLEM SOLVED!!! Ryan, Mike, David-I appreciate all of your responses and time! Best wishes!