but the kids use it so guess it's OK, except they cannot view HD videos, they lag. That is the main reason i wanted to change the processor, thinking it would be faster. I have added 1GB ram, Nvidia Geforce 6200 already..
At what resolution, display size and what player is this HD content shown on?
This can be a GPU driver or VGA card problem also.
The 6200 AGP is a weakish card, especially if it is an LE version.
Here an example of 6200LE vs. ATI HD3450 AGP
I think the GPU offload for HD content will work better on say a HD3450.
Even better would be the HD4350 AGP, e.g.