If you have an ISO file which contains bootmgr and boots to WinPE, then you can use it with E2B by renaming the file extension to .isoPE or .isoPE01. This only works if you have a Removable E2B USB drive (you should convert the ISO file to a .imgPTN file if your E2B USB drive is of the 'fixed disk' type).
Note: There was a bug in previous E2B versions when using .isoPE and .isoPE01 file extensions (the blue LOADISOPE.cmd console window stopped with an error and the ISO was not loaded). You will need a recent version - e.g. E2B v1.81 Beta from the Alternate Download Areas (see side bar).
However, if you use the .isoPE file extension, it will cause E2B to immediately load and run bootmgr and so the ISO will boot straight to WinPE and you won't see the non-Windows boot menu, if one was present inside the ISO.
Note: There was a bug in previous E2B versions when using .isoPE and .isoPE01 file extensions (the blue LOADISOPE.cmd console window stopped with an error and the ISO was not loaded). You will need a recent version - e.g. E2B v1.81 Beta from the Alternate Download Areas (see side bar).
However, if you use the .isoPE file extension, it will cause E2B to immediately load and run bootmgr and so the ISO will boot straight to WinPE and you won't see the non-Windows boot menu, if one was present inside the ISO.