Need help fixing pc video problem

I have a problem with my computer playing anything video. If I watch a movie clip there is small stutters. Also when playing a game there is small stutters. I notice it even when the game is loading in and the company title animations are playing when you first boot the game. Then in game everything is running smooth but there is a small stutter every 5-10 seconds. The sound doesn't stutter in a movie clip but does a little in games. I loaded all the new drivers for my video card and tried reformatting my HD. I have a 9NPAJ epox motherboard with an athlon 64 3800. My video card is a leadtek PCI-e 6800 tdh. I have 1 gig of ram. I am running the newest version of the nforce4 drivers. I tried the newest version of the leadtek drivers for my card and the drivers from the cd that came with the card. I just can't seem to figure out why there are these small stutters in video.

Check if you have some sort of heat related problem with your vga card.

The game I was using was COD2 single player demo. So there was no online play that could have been causing lag. Since the demo was on my HD it wasn't reading anything from cd/dvd. Would a drive check on the cd/dvd drive still causing a stutter/lag. I will have to check the background apps and see if the video card is getting too hot. Although inside the case my temp probe is reading 79 degrees.

Well I just checked the temp after it had been running some basic apps. The inside of the case was 91 degrees F. I closed all the programs in the backgrounds except msn messanger, but there was still the stutter. Any other ideas?

Ya, true the vid card still could be hot. I will have to try and get a reading somehow. What if I boot it up after it has been shot off for like 5 hours or something giving it time to cool? Wouldn't the problem be gone until it heats up again?

Ya I was thinking about finding another vid card to drop in to see if it would fix it. I don't have anyone around that has a newer video card, but I think I can salvage a 4 year old vid card and see if it smooths the video out. If a different video card smoothed it out; do you think it is a heat problem? Or would it be a bad card problem?

I dunno, I am going to check that one.

well I just played a different video and streamed a whole bunch and had no problems. I am just having problems with the one video clip before having the stutters. That is why I thought it was related to the COD2 demo. I am downloading the BF2 demo right now and I am going to see how that is. I felt the heat sink on the video card and was feeling around inside the case and everything was cool and not hot to touch at all. Maybe the games will run smooth now that I have reformatted? That one clip I have problems with runs smooth on my laptop. That is why it seemed very odd. So now I am really confused.

yep you are right, it must have been something else. I just ran the bf2 demo for like 2 hours (addicting game) and it was silky smooth. Except for it locking up a bit in this one spot when I was gunner on a truck. I cranked all the settings up and it still ran great. I know what game I am buying tommorrow Now I just need to get a nice new lcd monitor since my 19 inch samsung crapped out on me. I am playing on a 8 year old 15 inch NEC now Thanks for your help everyone.