You can look inside MEMTEST.IMG with 7-zip and see it won't boot. It just has literally 2 image files. It will not boot. Also I tried it, I tried burning it from windows. I haven't tried converting it ...
If VirtualBox is not booting from ISO or if GParted ISO is not mounting, correct the Boot Order in System Settings and verify ...
Trying to get started with VMware’s virtualization app but lack an optical drive on your server? Here are the steps to transform the ISO into a bootable flash drive for installing the hypervisor.
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