You want to create an WIM file from your Reference Windows machine. The reference machine is prepared with all necessary software and you sysprep this machine using:
sysprep.exe /generalize /oobe /shutdown /unattend:unattend.xml
Note: unattend.xml must exist in C:\Windows\System32\sysprep
To create a WIM file you need to boot in Windows PE mode and after that use Image.exe to capture the image and copy to network share, HDD or USB drive.
To boot from Windows PE you have to create Windows PE bootable USB drive:
After that, copy ImageX in the root of the USB drive.
ImageX is included in Windows AIK software. For Windows 7 you can download it from this site:
There are different versions of ImageX which depend from computer architecture. For 64-bit machines ImageX is located in following folder:
C:\Program Files\Windows AIK\Tools\amd64
When your booting in Windows PE mode is done, press F8 to get command prompt.
By default CMD is redirected to X: drive.
In my case USB drive was F: drive. To execute ImageX command I switched to F drive and from there first I mapped network share using:
net use y: \\server\network_share\
After that to capture and to copy WIM file to network share I used:
F:\imagex.exe /capture c: y:\myimage.wim "Drive C" /compress fast /verify
C drive is currently the drive that was syspreped and that has to be captured and copied to network share.