Lösung :
Win 7 habe ich jetz am laufen, Lösung :
1. Create a new Virtual Machine on your Hyper-V (Server 2008 R2).
2. Install Windows 7 from a DVD or an ISO file, whatever makes you happy.
3. On the final reboot of the install, you will, of course, get the above mentioned black screen.
4. Reboot the VM, but this time press a key to boot from the Windows 7 DVD (or boot from your ISO) so that you can get into the repair mode (recovery console/DOS prompt).
5. Type C: to go to the C (boot) drive of your Windows 7 VM.
Here's the magic:
6. Simply type the following command at the recovery console DOS prompt:
bootsect.exe /nt60 all /force
7. type EXIT and then reboot the machine.