Media problem

[Powman]

Just recently my comp. has been having a lot of problems, one of those, to which I am reffering is a problem viewing buffered videos on video sites. I.E. Google video. I've had no trouble viewing these in the past, but now, whenever I play them, even when they are fully loaded and buffered only play for about 2 seconds and then stop, even if I click somewhere else in the clip, in only plays for that amount of time. There is also no sound whatsoever.
I can play downloaded videos and songs that I already have.
I'm running windows 2000, and have only encountered something like this in the past when having trouble with the sound card installation, in which any media would play only in short bursts.
Any help is appreaciated.

 

[PC eye]

If you are not finding any problems with the sound in general the simple cause may be a need for specific codecs for both video and sound. Is there a player provided at these sites or do you see Windows Media Player or another type open to run these?