I got power DVD with my ati 9500, and win DVD with my motherboard. Does power DVD work better with ati cards, or do they both work equaly as well. Can I install both without them conflicting anyway?

Yo man
Powerdvd has better video quality and audio quality.
Also powerdvd has better sound and video options.
I use powerdvd, and i recommend you do too.
But windvd is fine too.

Both are almost exactly the same. You didn't mention what versions you got, but if one is later than the other you might find it works better. (sometimes you get really old versions in the bundles)

The later versions of both have full hardware support for ATI cards so it's really upto personal prefrence as to what you use.

Chicken's right. ATI used to base their DVD around the Cinemaster codec, now all the new ATI DVD software is basically PowerDVD with a slick interface. I used to get a better picture quality out of ATi/Cinemaster, but 5.1 audio would take a dump big time with the Raviscient audio codec (skip, out of synch, etc.) The new PowerDVD is right up there in IQ now, and the sound has always been better.