@GTAXL
You can use imdisk to mount img file as a virtual drive, see the attachment picture.
https://sourceforge.net/projects/imdisk-toolkit/
As Steve2926 said, you can also make a 3rd partition on the USB drive with the reservced space, format it in FAT32 and extract the memtest86 files to the partition.
https://www.ventoy.net/en/doc_disk_layou...erve_space
You can use imdisk to mount img file as a virtual drive, see the attachment picture.
https://sourceforge.net/projects/imdisk-toolkit/
As Steve2926 said, you can also make a 3rd partition on the USB drive with the reservced space, format it in FAT32 and extract the memtest86 files to the partition.
https://www.ventoy.net/en/doc_disk_layou...erve_space