I have seen this happening a few times, mostly on Hyper-V guest machines.
The solution is simple.
Boot using the CD or ISO and press SHIFT + F10 to get a command prompt.
Type bcdedit and press enter
You should see the windows boot manager in one partition and the loader in another one. If that’s the case, then type:
bootrec /fixmbr and press enter
bootrec /fixboot and press enter
reboot computer
If that was not the case, try typing:
bcdboot C:\Windows
But make sure the Windows directory is in the C drive, if it is not, replace with the correct letter.
Many thanks to <a href="http://fbinotto.blogspot linked here.co.uk/2011/08/windows-7-wont-boot-black-screen-with.html”>Felipe Binotto’s Blog.
Newly-built Windows 7 in Hyper-V shows black screen and flashing cursor after 1st boot