On older PCs and OSs, it's good to try the directx debug applet.
Just turn the debug levels down if they are up. This helps alot on emulators. You might even go back to DX8 if you are using 9. I'm just going by memory of my old pc and what helped and that was a Celeron 400 system. Going back to old graphics drivers is helpful also if you use NVidia or ATI.