registering codecs HD video?

[terramir]

my machine is highpowered enough to playback hd video but I' having a cpu and video problem :S
athlon xp-m 2600 @ 2300 Mhz (XP 3400 speed )
nf7-s ver 2.0
1 gig of pc 3500 memory
And this is what should put me on top of total suffiency
X1600pro 512 MB avivo video card.

However I still suffer from hacky playback and I have some severe problems with cpu usage it's still a constant 100%.
Because the X1600pro did not come with the dvd player I broke down and got the bought the ati cd so I could install the mpeg2 (dvd codec) but I am still having problems I thought this would off load it to the gpu but it seems like no dice.
Really need a codec tutorial please
terramir

[sub]

Have you tried using Overlay instead of VMR? Also make sure you're running on the primary monitor rather than second monitor, since hardware accelleration often only applies on the primary monitor.