Comment 15 for bug 958549

Thanks Jim Salter!
You point me to the right direction...!

Nevertheless I had choosen another way to solve that black screen issue because RDP to my Windows Machine wasn't possible.

I use virt-manager so I added a new video device to the VM.
The order is important: the first Video device must be "Cirrus" and the second one must be "qxl".
Boot up Windows VM
Download and install the latest spice-tools within Windows VM
Shutdown Windows VM
Change first video driver back to qxl
Remove second video driver
Boot up Windows VM
Enjoy ;o)

Ah yeah and well I had some other problem here when booting up: Windows told me that the Redhat QXL driver is not signed and therefore it refuses to load that driver!!!! I use Windows 7 - 64 bit and as you can read here:
http://lists.freedesktop.org/archives/spice-devel/2011-May/003814.html
The SPICE Team do not deploy signed drivers for 64 bit Windows.. You have two options to solve that: The hard and correct way as described here:
http://spice-space.org/page/WinQXL#How_to_build_the_driver
or to use the test-mode and test-sign the Redhat QXL drivers (right click within the device manager and then "Driver details" will show you all QXL drivers you need to sign than) like described here:
http://www.ngohq.com/?page=dseo

My tip: Remove the second video driver in virt-manager only when the QXL driver is fully working.

Issue may occuring for you, too:
When you have the QXL driver running correctly (no warning icon in device manager) and your Mouse/Mice stops working this is a known bug in libvirt - you only need to shutdown the VM and do the steps above which removes the second Video card. Afterwards when you boot up your mouse should work again (if not try to remove the mouse in device manager and reboot again)

For me running testmode is ok and it works like a charm ... so great desktop resolution ;o)

Hope that helps someone out ;o)

Hint: no BIOS display though.

Regards
Thomas