I recently had an unknown error with my Dell Inspiron 15 3521 that prohibits me from booting, and as I have a lot of sensitive/important data on it, I tried to boot Ubuntu from a DVD to try to recover my data. I don't know how to do this, as my BIOS does not have a boot order selection. Please assist.

It is from 2013, and runs Windows 8. I can get to the boot menu, I just can't find how to make it boot from the DVD drive.

  • 2
    Usually, for DELL machines, you need to spam either F2, F12, or (possibly) Delete while the machine is booting up. Try Googling dell inspiron 15 3521 boot menu. Dec 16 '13 at 20:27
  • Or sometimes Esc will work if its a newer machine Dec 16 '13 at 23:19
  1. In the BIOS system setup screen, go to System -> Boot Sequence. If System has a + sign in front of it, you can click on the + sign to unfold the options for it.
  2. You will see a list of devices that BIOS searches for when you boot the computer. Only devices that are preceded by a number are bootable.
  3. Press Up/Down arrow to select a device.
  4. Press U/D to move a device Up or Down in the list.
  5. The Space key controls whether a particular device is bootable. Press Space to enable or disable a device.
  6. Press Enter when done modifying this field.
  7. Save & Exit

enter image description here


You have to set "Secure Boot" to disabled, and I would put "Boot Option" to legacy just to be sure. UEFI with Secure Boot does not allow for Legacy boot options which include things like DVD, USB, etc.


Well if your computer is new then chances are it has UEFI BIOS.If that is the case then boot sequence might not show USB/DVD options because the windows you are trying to install are not UEFI compatible. If your system allows you to, then set the boot mode to Legacy mode after turning secure boot off.Then follow steps in the first Answer. if you dont have legacy boot then you might have to get a version of windows which is UEFI compatible.

  • 1
    Welcome to Super User! This duplicates another answer and adds no new content. Please don't post an answer unless you actually have something new to contribute.
    – DavidPostill
    Jun 15 '15 at 10:42

I had the same problem on an Inspirion 13.

The solution was to plug in a USB keyboard and press F12 repeatedly during boot-up.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.