I'm happy now I installed win8.1 on a second partition and ran winbuilder from it, but before pressing play button I hadn't copied files from WAIK, only bcdedit.exe from system32 and mounting with imagex passed well.
What type of drive is drive d:? It must be an internal hard disk / ssd for mounting to work. An external USB hard drive may work as well as long as its not a removeable drive.
D disk is internal sata2 hard drive, 1tb capacity.
Now I want to try replace that files from WAIK to winbuilder path and see the result.