Some of the system RAM might still be faulty if XP isn't installing.
though do this with Power DVD:
Press the Configuration Button, then go to the Video tab, and Disable, or Enable Hardware Acceleration, depending on what its on now.
Plus press Advanced in the Video tab at the bottom, and try changing the resoloution of movies to a lower, more friendly setting.
then, check in the Audio tab that you are not running any 3D surround settings, so keep it at Stereo.
I hope this helps