I'm trying to boot Lubuntu and elementary OS from a USB stick, but the laptop stops with the message "you need to load the kernel first." It also sometimes reports an "invalid magic number." Secure Boot is currently disabled, and I've tried both UEFI and Legacy boot modes. I created the USB with Rufus after having problems with another USB tool. The laptop has an Intel i3 processor, 8 GB of RAM, and integrated graphics. What should I check or redo?
2 Answers
“Invalid magic number” usually points to a corrupted ISO, an incomplete download, or a problem writing the image to the USB drive. Download a fresh ISO, verify its checksum if possible, and recreate the installer carefully with Rufus. If you can, also test with another USB stick. Use GPT and UEFI mode for a modern laptop rather than mixing UEFI and Legacy settings.
Start over with the distribution’s official installation instructions. Keep the firmware set consistently to UEFI, and don’t switch between UEFI and Legacy for the same installer. Secure Boot can usually remain enabled for current Ubuntu-based distributions, although disabling it temporarily is also fine for troubleshooting. If the error continues after recreating the USB, the ISO or flash drive is the most likely cause.
Thanks, I’ll recreate it from a new ISO and stick with UEFI instead of changing modes.
I was using Rufus, but I’ll download the ISO again and try a different USB drive if necessary.