I am successfully using a merged install.wim containing the x86 and x64 editions of Windows 7. The unattended installation also runs though as intended. However, when I also add the Server 2008 R2 to the image, setup fails during the WindowsPE pass with one of two errors: "A requird CD/DVD drive driver is missing ..." "Windows cannot open the required file E:\Soures\install.wim. ... Error code: 0x8007000D" (I only got this lately after changing my sort order a bit) My mkisofs settings are as fo