Windows on BootCamp cannot start upon a fresh installation
This basically is a repost of the following sites:
get "appleSSD.sys" error when installing windows 7 through bootcamp and
bootcamp - appleSSD.sys digital signature can not be verified

Looks like there are problems with Boot Camp Support Software (BCSS) being downloaded from Apple. Here is a solution:


Download an older version of the BCSS for your Mac. See
System requirements to install Windows 7 and earlier on your Mac
using Boot Camp. In your case, the software can be found at Boot
Camp Support Software 5.1.5621.
Using Boot Camp Assistant, prepare the USB flash drive. Select the
first two items and prepare the disk.
Quit Boot Camp Assistant.
Using the Finder, move the $WinPEDriver$ and BootCamp folders
from the USB flash drive to the Trash. Empty the Trash.
Using the Finder, copy the $WinPEDriver$ and BootCamp folder
from the BCSS to your flash drive.
Reopen Boot Camp Assistant and select only the third option, install
Windows.


An explanation regarding the purpose of these folders can be found at Limitations of $WinPeDriver$ when used in conjunction with other driver injection methods.