I've been building out a new windows 7 image and ran into the BOOTMGR is missing.  I let it sit for a night and it came to be -- there's an extra partition on win7 that vista didn't have.  Ok, makes sense because I applied the image to C:, in my case, that's partition 1 on disk 0, it should be disk 1.  Hmm, so there must be a way to do this and of course there is.  So let's jump right in.

I downloaded the new WAIK (Windows Automation Install Kit) and its huge, 1.66GB by my download box thinking there was some new magic I wasn't aware of.  There isn't BUT there's a "new" step.  Within the kit, I found the following ... 

diskpart
select disk 0
clean
create partition primary size=200
select partition 1
format fs=ntfs label="system"
assign letter=c
active
create partition primary
select partition 2
format fs=ntfs label="Windows" quick
assign letter=d
exit 

Which is great, unless you have cd drive and that windows volume you just created is no where to be found.  Just restart and it'll be there.  Dump your image and run D:\windows\system32\bcdboot d:\windows and that should do it.