When attempting to add a new 'pre-boot operating system' (winpe 3,4,5 or 10) via BootWiz the message ''Do you want to install the WimFltr driver" is displayed.

'Do you want to install the WimFltr driver'  is displayed

DS 7.5, 7.6, 8.0, 8.5

GSS 3.x

The WimFltr driver error is a red herring because WinPE 3.0 and later no longer use the WimFltr driver.  (See KB TECH40267 for winpe2.1 information regarding the wimfltr driver) . The issue is that the Wimmount.sys file in not being loaded.

The path in the registry to 'Wimmount.sys' is incorrect.

To fix this issue please do the following:

1. Open the registry with 'regedit
2. Browse to 'HKLM\system\ControlSet001\services\WIMMOUNT
3. Make sure the image path is correct for the approriate WAIK kit.  E.g  The path to the wimmount.sys file for WinPE 10 is '\??\C:\Program Files (x86)\Windows Kits\10\Assessment and Deployment Kit\Deployment Tools\amd64\DISM\wimmount.sys'. 
4. Repeat step #3 for Controlset002 and CurrentControlSet
5. Reboot the server.