Problems with videos and 2D

i have a Pentium 4 3.00ghz, with a geforce fx5500 and 512Mb ddr400 (2x256)

and a celeron 2.66ghz, with a geforce mx4000 and 256Mb ddr400.

i'd downloaded a HD video, and runned it on the 1st PC, the sound was normal, but i was getting something like 1 FPS, and them, i runned it in the 2nd PC, and it runned normaly.

in the 1st PC, sometimes i've problems in the web, when there are ads with animation, the comp gets really slow, but it don't happens in the other PC.

But for 3D, the first one is much better.

what can i do to make the 1st one runs 2d aplications and movies like the 2nd PC?

obs: when i watch DVD movies in the 1st PC, it's normal, but i'm having problems with some games oppenings, like AOE3:

this is (or should be) ensemble studios logo.

Get the latest drivers for your video card at www.nvidia.com if that doesn't work reinstall all your codecs.JigglyWiggly2

i've already done that 

Get the latest drivers for your video card at www.nvidia.com if that doesn't work reinstall all your codecs.JigglyWiggly2

i've already done that 

Did you uninstall the old drivers, used a driver cleaner after that and then installed the newest drivers?DirkVDV01

i'll try it 

Did you uninstall the old drivers, used a driver cleaner after that and then installed the newest drivers?DirkVDV01

i'll try it

EDIT: sorry, double post(again)