To create a bootable media by using a .wim file, you need to convert it to an .iso file first.
To create a PE image (.iso file) from the resulting .wim file:
Users of Windows 7 should select Microsoft Windows AIK ® Deployment Tools Command Prompt from the Start menu.
If you create WinPE 4.0 ISO, select Windows Kits ® Windows ADK ® Deployment and Imaging Tools Environment from the Start menu.
copype amd64 c:\winpe_x64
For WinPE 3.0, type:
copy c:\AcronisMedia.wim c:\winpe_x64\ISO\sources\boot.wim
For WinPE 4.0 or WinPE 5.0, type:
copy "c:\AcronisMedia.wim" c:\winpe_x64\media\sources\boot.wim
oscdimg -n –bc:\winpe_x64\etfsboot.com c:\winpe_x64\ISO c:\winpe_x64\winpe_x64.iso