There is a manual fix for this which is to use SHIFT+F10 to open a Windows console and then run the \_ISO\e2b\firadisk\LOADISO.cmd file. See https://easy2boot.com/testing-e2b/using-qemu-or-virtual-box/
The other way is to make a .imgPTN file from the Windows install ISO. If you do this then not only will it work from a hard disk, but you can also install when booting from a UEFI system too. You can also try the .imgPTNAUTO file extension to avoid the warning text before it switches in the partition image.
Subject Re: Running a Cosair GTX 128gb usb flash drive