How to add unsigned driver to boot image

You might have been running into the error massage below, but what to do when you only have an unsigned network driver?

Wizard-Error

1. Click “Start menu”
2. All Programs
3. Microsoft Windows AIK
4. Run “Deployment and Imaging Tools Environment” as an administrator
5. Mount boot image:
Mount

C:\>Dism /Mount-Image /ImageFile:"S:\wds\boot\x64\images\LiteTouchPE_x64.wim" /index:1 /MountDir:"S:\WDS\Boot\x64\Images\offline"

6. Inject driver:
InjectDriver

C:\>dism /image:"S:WDS\Boot\x64\Images\offline" /Add-Driver /Driver:"\\server\windows\Drivers\IBM LENOVO\Test\Lenovo X1 20BS\Ethernet\N10RW12W\e1d64x64.inf" /forceunsigned

7. UnMount image:
UnMount
C:\>dism /unmount-image /mountdir:"s:\WDS\Boot\x64\Images\offline" /commit

Enjoy!