hope someone can help ??

i have xp home on a dell dimension 4400 with over 600 mb ram.
the vidio on my pc if it be looking at a dvd, or tv on my pc , or games on my pc. or even the animation on msn home page adverts, the picture pauses for about 1 second every 3 or 4 seconds causing the picture being viewd to be jerky, but is only aparent while watching any of the above , ive changed vidio card's and done a fresh install with no change in the effect and now quite dont know what to do
hope someone can help
mal

Have you always had this problem or did things work OK previously?

You reinstalled XP with no difference?

What type of card are you using?

Have you tried uninstalling and reinstalling the drivers?

Perhaps using a driver cleaner as well?

Are you doing anything else when this happens? Running other programs etc.

Open your Task Manager (right click an empty area of the Task Bar) and note your CPU Usage.