Help with playing hd video? (lagging)

Hey so Ive been trying to play a few videos that are 720p. I tried playing them from my hard drive and they were lagging and becoming very pixelated every few seconds along with the audio lagging. I thought maybe i had a problem with my external drive so i transfered them to my computer but had the same problem. Any advice or tips are greatly appreciated. My setup is below.

Macbook Pro 15 inch running snow leopard (10.6)
2.16 ghz
2 gb ram
any other info i need to give?

Thanks

JACK

I'm not familiar with Macs at all but what type of graphics card does the Macbook Pro have?

I have the same problem with 720p files

I have Intel (R) Pentium (R) 4 CPU 3.20GHZ
3.19GHz, 0.98GB of RAM Physical Address Extension

Windows XP Professional N Version 2002 Service Pack 2

I have the same problem with 720p files

I have Intel (R) Pentium (R) 4 CPU 3.20GHZ
3.19GHz, 0.98GB of RAM Physical Address Extension

Windows XP Professional N Version 2002 Service Pack 2

you should have no problem playing 720p files. What vid card and please turn off programs running in the background.

I have Intel(R) 82865G Graphics Controller and i update it but still i have same problem i can play 480p file only and what do you mean by the programs running in the background??

My video card is Intel(R) 82865G Graphics controller and I just found that the total Memory is 96.0 MB which is out of 1 GB of RAM and it is unchangeable.
So what do you think is better is adding a new video card or changing the motherboard (which is less risk?)

My video card is Intel(R) 82865G Graphics controller and I just found that the total Memory is 96.0 MB which is out of 1 GB of RAM and it is unchangeable.
So what do you think is better is adding a new video card or changing the motherboard (which is less risk?)
Why don’t you download the CoreAVC trial and use it to play your 720p files (video.mkv) to see if the lagging goes away.

Like oblioman said, your cpu is more than strong enough to handle 720p; so either your codec or vid card sucks.

Do you have a Dell? If you do, changing the video card is less risk and an easier replacement, but try Coreavc first.

I have Intel(R) 82865G Graphics Controller and i update it but still i have same problem i can play 480p file only and what do you mean by the programs running in the background??

get a vid card. One with at least 512 meg of ram. Programs running in the background kill your computer. Do a Ctrl -alt-del and bring up your task manager. If you have more than 30 items listed,,,you have to much stuff running. Anti-virus, update schedules, print spoolers, ipod crap, MS office,,,,,all that kind of stuff should be knocked off the list. You can right click and end the process from the task manager, but upon re-boot, they will return. you have to enter the admin services to completely kill the junk.