I try to turn off secure boot in every BIOS. I've missed some so booting Ventoy is tricky.
Here is an option that has worked for me.
Boot the PC and launch Boot Selector (F8, F12, F11 or look it up)
Select the USB disk
Enroll Key From Disk
VTOYEFI
Enroll_This_Key_In_Mokmanager.cer (or closest name)
Continue
Yes
Reboot
Ventoy should boot.
A recent quirk I had with booting Hiren. The laptop only had 4GB of RAM and Hiren wouldn't boot. AI was telling me it was a Secure Boot or UEFI problem. No clear error message was given but I'm sure it was not enough RAM. Later I booted the same Ventoy/Hiren on a secure boot laptop with 32GB RAM.
It can get confusing if you haven't enrolled a Ventoy Secure Boot recently.
On reboot you will need to hit the boot selector key again and choose USB drive.
