Cannot boot off USB after installing an OS

I messed up during my OS installation and lost the root password. I need to boot off a USB disk to fix it or reinstall but I cannot. I see the USB drive in the bios menu but it doesn’t show up in the boot manager when I press F12 during boot.

This is the exact same USB decide and disk image i used to install linux earlier. Secure boot is disabled and i tried only plugging in the device once I was in the F12 boot menu.

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Holding down FN and pressing F12 on repeatedly is what I do. Works every time. That should bring up the EFI boot menu.

Also I leave the USB drive in there, I don’t unplug it prior to booting into the EFI Boot menu, I have had it where it does not show up in that menu unless it’s there before/while i boot that menu.

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I’m sorry I must not have been clear in my post. I can get to the EFI boot menu but the USB device is no longer showing up in it. However, the USB device does show up in the bios menu.

I have disabled secure boot (which I had to do initially to get the machine to boot off USB when I installed my OS) and I have tried every combination I can think of as far as when to plug in and/or unplug/replug the USB device at different points in the boot process and the EFI boot menu.

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For whatever reason, reflashing the same USB device with the same disk image allowed the laptop to boot off of it.

I saw the same and posted. Why would re-burning the media do this? Very bothersome…

The ISO needs to be exactly right for the installation to work. In my experience they typically download just fine, but I’ve had a few cases where the file was messed up somehow. That’s why typically an ISO is presented with a checksum (usually sha256) so you can verify the image was downloaded perfectly intact.

Otherwise…it might take you a couple tries. :joy: