Can no longer boot from USB - SOLVED [Solved]

[PeterO]

I have some Lenovos, some rather old, at least one more recent. All of them goes into CMOS settings using F2.

Sometimes I have had similar problems as OP reports, refuse to even see an USB in the CMOS. The best way around this for me has been using Rufus for creating the boot USB, which has never failed (uhum, yes, MX boot created USB has sometimes failed).

It is rather unusual for a pc not to have a CMOS battery. At the same time, they seems to last nearly forever. Not always mentioned in documentation.
Anyhoo, as long as there is power supply to the pc it should not be the battery. Just ensure that power supply is fully ok during the CMOS setting and boot.

[fehlix]

I can set the boot order, restart and it boots to the hard drive
..
Looks like the boot order setting is lost before restart - when I go back in again with the USB still inserted, USB is not the first option.

UEFI bootmenu is not static, it get assembled with every boot. Best use UEFI boot options menu through a Fn-key like F12.
* Suggest to try to boot from a GPT USB instead of the default MBR/DOS usb created by MX Live USB Maker. GPT can be set under Advanced menu in LUM.
* If still not, try to create a Ventoy Live USB - do also select GPT instead of default DOS.
Copy the MX ISO onto Ventoy. If Ventoy stick boots select MX ISO to boot.
* Else get rEFInd ISO or betterr Refind-USB-img and dump rEFInd img to a small USB
In case it boots from rEFInd usb, have MX LiveUSB also plugged in, refind will search and lists the found MX Live USB to select.

In case nothing helps, change within UEFI System setup (aka BIOS) disable UEFI boot keep only DOS/MBR / legacy BIOS boot.
If that boots you would be able to install in MBR/DOS mode, with the suggestion to recreate a new DOS partition table, which wipes the current gpt-drive. Keeping gpt for mbr-boot is also possible with an additonal bios_grub partition.
HTH

[peregrine]

Thanks to everyone for the suggestions. I am now able to boot using Ventoy.

[richb]

Please mark the topic solved by clicking on the check mark at the upper right of the post that solved your problem.