XP bare minimum requirements for graphics card is 32MB.
You've just got 64MB, don't expect graphics to be good. It works
fine as long as it's not 3D intensive. Don't believe, run a 3D
benchmark test. It will fail horribly. I've gotten a lowly 6 points
and I think it nearly hit negative.
Talking about jerky graphics, did you install your graphics
drivers? Windows default drivers don't necessary work. Grab your
motherboard CD, put it in and install the graphics drivers. It
should be better now.
As for your Net speed... LatecomerX will deal with you.