Why I Get a "Bootmgr is missing" Error When Diskless Boot Windows 7?

That's because of the HDD on the client from which the image has be uploaded, some particular partition model may lead to this error. So please format the HDD, install Windows 7 to the first partition and then upload image again.

Expired since CCBoot V2.1 released.

More information: windows 7 lan boot - pxe boot windows7