I'm using Ubuntu 14.04 and like it very much but I can't update anything because I forgot my password and authentication is required. This is a home computer and I am a single user who doesn't even care about passwords.

I've done a lot of research and have tried the routine password changing steps .. recovery mode .. mount -rw -0 remount / etc.. which got me “authentication token manipulation error password unchanged. I’ve read the threads and tried the fixes with no luck.

You know in the beginning I might have set my password before I set the time/date and another guy who did that got the same message and claimed that that had caused his problem. He fixed his by deleting the encrypted password in the /etc/shadow file and then doing thesudo passwd username fix to create a new password. He never said how he deleted the encrypted password and that is where I am stuck trying his fix. When I look at cat /etc/shadow I can see the encrypted password right next to my user name but I can't get into the field to delete it.

Where and how do I delete this password so that I can create a new one.

Any help would be greatly appreciated.


  • Try Bernard's solution (passwd -d <username). – muru Feb 15 '15 at 19:45
  • The remount command should be mount -rw -o remount / or mount -o remount,rw / (the option switch is -o not -0) – steeldriver Feb 15 '15 at 19:49
  • None of the answers in the linked questions worked? Even this one askubuntu.com/a/266608/129271 or just appending single to the GRUB boot line (around the quiet splash if they're there)? – Xen2050 Feb 16 '15 at 6:57
  • First, deleting /etc/shadow without having a backup is a bad enough idea. Second, it's not mount -rw -0 remount / but rather mount -rw -o remount /, it's not zero, it's letter o. – Sergiy Kolodyazhnyy Feb 17 '15 at 1:52
  • Follow this answer to delete the encrypted password. – Seth Feb 21 '15 at 19:44

If you cannot find any solution, you could just create a new partition, install Ubuntu on the new partition, and then transfer all your important files from your previous installation. Then format your old partition, then add the unused space to your new partition with your new installation. Here's a rundown

  • Download a Ubuntu 14.04 LTS ISO from their website here (http://www.ubuntu.com/download/desktop)

  • "Burn" the ISO to a USB or disk. You can use "Startup Disk Creator", which may come package with Ubuntu, if not you can find it easily in the Software Center. Open that and make a startup disk using the previously downloaded ISO. To select the ISO, you need to click the disk and navigate to it. Also, you'll need to format the USB, so make sure you don’t' have anything important on it.

  • After it is burned to the USB, restart you're computer and spam F12 while it starts up. It should bring you to the "boot menu" which allows you to choose what to boot off of

  • Choose your USB device from the menu with the arrow keys and hit enter.

  • A pink screen will show up, hit down and it will bring up a language menu, choose your language, and then choose install Ubuntu. If you get a black screen after that for longer the a min, restart your computer and redo the previous 2 steps and when you make it back to the pink screen after selecting a language, you'll want to hit F6,a small menu will pop up and navigate to where it says "nomodeset" and hit enter on it. Then try installing again.

  • When you install, set it up like you normally would until you make it to the menu that asks how you want to install it. You will want to choose "Something else" at the bottom of the menu.

  • Now, here's where things might get a bit confusing since I don't have much information from you. If you have only a single partition, you need to resize it. Double click the partition and reduce the size (preferably to half of what it is) and click ok.

  • Now, you want to create a new partition, click on the free space and create and then click on the plus sign button. You want this to be leave the settings alone other than the mount point, which should be the root folder "/". Hit ok and continue. If it says you need swap space, you can ignore it if you laptop was running fine without it previously.

  • Continue through the installation, its fairly simple at this point, it just asks for you to make a local account, and after that you should be good to go :)

  • Now, after you log into your new account, click the icon on the top left corner and type in "disks" and click the first link. You will see all your partitions on your hard drive. You want to make sure your old partition is mounted, if not, click on it and mount it.

  • Now, use Ubuntu's file manager and copy any personal or important files from the old installation of Ubuntu (probably the entire home folder, that's where most of your important files would be).

  • Now, go back to disks, click on your old partition, and format it. Now, you can readd this empty space to your new partition, and your good as new.

Any questions just ask, I might give you a link to some info that might be more helpful :)

| improve this answer | |
  • 1
    Perhaps a little more details would improve your answer. How about a step by step procedure ? – Sergiy Kolodyazhnyy Feb 15 '15 at 23:59
  • Now that I think about it, there are quite a few different ways going about installing Ubuntu, I assumed that they used a cd or usb and copied an ISO. I'll give a rundown give me a couple min – Aaron Flores Feb 16 '15 at 0:36
  • I was very detailed and stated this as a last resort, not sure why people are voting it down. If I made a mistake, tell me and I can fix it -.- – Aaron Flores Feb 17 '15 at 1:22
  • Well, it's pretty detailed , which is good. Not everyone who down votes leaves a comment here – Sergiy Kolodyazhnyy Feb 17 '15 at 1:48
  • Well i mean, if I they downvoted me for a reason, I'd like to know why so I could improve the answer – Aaron Flores Feb 17 '15 at 2:01

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