2D Accelleration not available?

[Thomasio]

I´m running a couple of XP guests on a Win7 64bit host.
So far I´ve never had a problem, at least not with display settings, but now (after system-reinstall) I must have messed something up, or in short:
The checkbox for 2D acceleration (it´s a german version, so not sure about the english word) is greyed out and can´t be activated anymore.
Could anyone tell me, how I can activate this again?

If needed:
My PC is an I7 860, 8GB RAM, the VM is set to 2GB RAM, 128MB graphics, VT-x and all the other system settings are enabled.

[Winipulator]

I'm assuming the graphics driver for your host OS has been installed correctly. In the XP guest, did you install VirtualBox Guest Addons in safe mode? If not, this is the thing to do. Also, in the VM settings, I have Nested Paging disabled, because its caused graphics issues with me in the past. Good luck to you.

[Thomasio]

Thanks for the answer.
Meanwhile I´ve been digging around and I found some further info about this topic.
NVidia graphics drivers do not all support the functions needed for VB´s 2D acceleration, it seems to depend on version, where the default driver Windows7 installs doesn´t work.
Also some versions crash the VM when 2D acceleration is enabled, I´ve tried with the latest driver from the NVidia website and it crashes the VM upon boot.

So the question has become a new one now, because I haven´t figured out yet which version works properly.