Firstly, I recommend reading up on the Windows 7 deployment guide. With Vista/Win 7 deployment is a whole new ball game.
I do the following for a successfull deployment, after having captured my image using ImageX:
Use a diskpart script to create a C:\ 100Mb SystemRestore partition and a D:\ Windows partition. Windows will fix the drive letters after reboot so that the Windows partition get the letter C:
Use ImageX to deploy the image to D:\
Use the BootSect.exe /nt52 C: and BootSect.exe /nt60 C: commands from within the eXpress\WAIK\.. folder (Not sure if this is necessary anymore, but it works so...)
Use the following commad to create the boot files on the 100 Mb partition: d:\Windows\System32\BCDboot.exe d:\Windows /s c:
Now, this is what really dows the trick. Note however that för 64-bit OS deployment you have to use the 64-bit PE and vice versa for the 32-bit OS.
Regards/