virtualbox.org

I'm using VB for 2boxing with a Windows XP Sp3 host and a Windows XP Sp2 as a guess. When I run my game on VB, it needs like 10 minutes to popping a window which says:

Enable. debug output for detailed information: -2005530518
Switching to the reference rasterizer, a software device that implements the entire DirectX 3D feature set, but runs very slowly.

Then freezes my vb.
I've installed DirectX SDK and DirectX 9.

I used THIS guide for allowing my VB to run dx apps.
The game's called Flyff and I know people who runs it on vb for 2boxing without any problem.

That guide is no longer valid, as it assumes that VB only provides OpenGL acceleration and you need the WineD3D libraries as stand alone. The Guest Additions now support DirectX for quite some time. Since 3.0 I think, but could be 3.1, I forgot. Anyway, boot the VM to safe mode, install the Guest Additions with the 3D option enabled and try again. If that doesn't work, then the guide is no longer valid and somehow the game just won't work any more.