If you have a large grub4dos-based (DVD) ISO which boots to a grub4dos menu and then loads other ISOs which are inside the main ISO file, although this may work as a DVD disk, it probably won't work if you try to boot it as an ISO from E2B.
If you examine the ISO file and it contains a \menu.lst and there are lots of smaller ISO files inside in various folders, then you probably have such an ISO and it will probably just hang if you try to run it as an ISO from E2B.
There is an easy way to get it to work however, just convert it to a .imgPTN file using MakePartImage and copy the .imgPTN to your E2B USB drive (make sure it is contiguous).
Acronis 2014 grub4dos ISO with multiple ISOs converted to a .imgPTN file
Just drag-and-drop the ISO onto the MPI_FAT32 desktop shortcut and answer Y (yes) when prompted to combine the menu.lst file inside the ISO with the CSM menu.lst file.
The new menu entries which have been added from the menu.lst in the original ISO should now hopefully run fine!
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