I'm trying to dual-boot Windows and Linux Mint 22.3 Cinnamon on separate SSDs. Windows is installed on a 2 TB WD Black drive, and I want to install Mint on a separate 2 TB Lexar drive. I created a 32 GB installation USB with Rufus, but stopped at the partitioning screen because I was worried about losing data. After backing up my Windows SSD, I tried booting the installer again and received these errors: "Failed to open \EFI\BOOT\MMx64.efi - not found," "Failed to load image - Not Found," "Failed to start MokManager: Not Found," and "import_mok_state() failed: Not Found." Recreating the USB with Rufus and Balena Etcher produced the same result. An Ubuntu USB created with Rufus boots successfully, but I would prefer Mint. I also tried disabling Secure Boot, although I may not have configured it correctly in the motherboard firmware. What is the best way to get the Mint installer booting without risking the Windows or backup drives?
3 Answers
A straightforward workaround is to use Ventoy. Install Ventoy onto the USB, then copy the Linux Mint ISO file onto it instead of writing the ISO directly with Rufus or Etcher. Boot from the USB, select the Mint ISO from Ventoy’s menu, and launch the live environment or installer. This worked for the original poster.
Before trying more installation commands, restore the firmware settings to their defaults, create a fresh USB from a newly downloaded Mint ISO, and verify that you are following Mint’s official installation instructions. Also make sure the installer is booted in the same UEFI mode used by Windows. Since the installation is going to a separate SSD, carefully identify the Lexar drive during partitioning and leave the Windows and backup drives untouched.
The missing MOKManager file points toward a Secure Boot or EFI bootloader problem. Try temporarily disabling Secure Boot in the motherboard’s UEFI settings, then boot the USB through the firmware’s boot menu. If Secure Boot is difficult to disable, restoring firmware defaults may help. Avoid deleting Secure Boot keys unless you understand exactly what that will change.
I tried changing the Secure Boot settings and booting through both the normal boot menu and the UEFI interface, but the same error appeared. I was hesitant to remove the existing Secure Boot keys.
I already tried resetting the firmware settings and recreating the USB, but it still would not boot. The Ventoy method finally got me into the installer.