I tried to install Ubuntu 11.04 on my laptop using thumb drive, but it failed, even though I used the standard Startup Disk Creator utility.

The laptop is a a Dell Studio 1536.

The problem shows as:

stdin: error 0
/init: line 7: can't open /dev/sr0: No medium found

What is the problem? What did I do wrong or what's wrong with boot loader?

  • Did you setup BIOS to boot from USB-drive?
    – Takkat
    Jun 5, 2011 at 14:18
  • Yes I did, I can even select boot device
    – sultan
    Jun 5, 2011 at 14:21
  • I've mounted ISO image from my home directory under the BusyBox shell, so the question is how to start the installation process from this stage?
    – sultan
    Jun 5, 2011 at 14:33

12 Answers 12


I've had the same problem the entire night. It's due to the installer not recognizing the USB drive after it's booted to BusyBox.

To fix this, you need to press F6 and modify the boot options. First, remove "quiet splash" from the options and add "break debug" in it's place. Continue installation as normal from this point. Eventually, it will break and you'll be presented with the BusyBox shell, and see plenty of the errors relating to this.

Are you ready for the next step? I promise you, it's an advanced manuver that even Han Solo himself would struggle to attempt.

Step 1: Unplug your USB drive

Step 2: Plug your USB drive back in

Step 3: Type exit and press <Enter>

Step 4: Wait 5-30 seconds and you'll be booted into your Ubuntu graphical installer.

Note: I've verified this works for Ubuntu and Linux Mint. I've been working on this problem for about 4 hours tonight and this is what worked for me, after trying every imaginable method of configuration flags for both the installer and BIOS. I am using a Toshiba Satellite C655D and using a 32GB USB 3.0 flash drive as the installation media.

I hope this helps someone, as I was about to go back to Windows after this nightmare.

  • 2
    Unbelievably this worked for me. I was shocked. Thank you so much! Mar 7, 2017 at 15:47
  • 3
    2019 checking in. This worked on 18.04.
    – Jim
    Jan 29, 2019 at 5:11
  • 1
    Glad to hear I am still relevant!
    – ITAdminNC
    Jan 29, 2019 at 18:17
  • I had the same problem trying to boot into live USB Ubuntu 20.04.3 LTS. I can confirm this solution worked like a charm, thanks so much @ITAdminNC ;) Nov 6, 2021 at 19:41
  • Worked for me! In my case, I re-flashed the drive using Etcher between steps 1 and 2, though that likely wasn't necessary. Dec 26, 2021 at 4:33

If you got this bug, when you boot from USB, press F6 then edit the boot option:

Remove this:


Add these:


Full sample:

append boot=casper initrd=/casper/initrd.lz live-media-path=/casper/ quiet splash ignore_uuid --

If you don't want to edit every time you boot from USB, you can edit this file in USB: /syslinux/text.cfg


  • Doesn't work, options already present. Jun 9 at 18:15

I found a solution in this comment on Launchpad bug 492301. If you've got this bug, when you boot from USB, press F6 then edit the boot options:

Add these:


This may be bug #492301

Try disabling Floppy in BIOS to find out.

  • My BIOS doesn't have this option, I don't know to disable this stuff(
    – sultan
    Jun 5, 2011 at 14:45

Befort the installation it should tell you that there are still some devices mounted. It will ask you to unmount them. Don't tell it to unmount them as it will also try to unmount your USB drive, which is the installation medium.


I got the same issue trying to boot Ubuntu 21.04 live CD on my Acer Swift 5 laptop, and none of the proposed solutions seemed to work.

Reading ITAdminNC's answer I realized I was also using a relatively large USB drive (32 GB).

Trying with a smaller drive (16 GB) did the trick for me.


We literally solved the problem by unplugging the USB drive WHILE the installation process was running, and replugging it back in another USB port on the PC.

  • This does work. Removed the USB and added to a USB-C port, and it worked! Dec 11, 2022 at 13:41

Choosing to install with option Safe Graphics solves this


I ran into the same problem today, while trying out the solution of ITAdminNC I spotted an error message that pointed me to my solution.

It appears that the USB bus cant power the USB Stick sufficiently for some reason. So I disconnected my USB SSD Harddrive and plugged the USB into a different port.

This fixed the issue instantaneously.

(this is the first contribution from a Linux newbie, so please forgive me any errors here)


I had the same problem. Solved by moving the usb thumbdrive to a usb port connected directly to the motherboard (back panel) instead of a port on the case and on a hub wich gave me this error.


I found that this was an issue with Legacy boot. I was installing pop os 21.04, and I was using CSM mode. The priority was set to legacy first, and since it is technically bootable in legacy, it booted. That seemed to break the installer, so I changed to UEFI first, and it worked just fine.


I don't seem to understand what happened in my case, buh literally pressing the f6 button continually did the trick for me

Running pop os 21.04 Nvidia installer on a 4gb 2.0 flash drive

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