Let me share a few points?

1. Norton doesn't do Parasites. In fact, it didn't stop Worms such as Sasser either.

Read up at http://www.doxdesk.com/parasite/

2. Microsoft doesn't do drivers. WE get to do that!

You have a Nvidia card, so try the drivers from www.nvidia.com or your makers site. After that I'd update DIRECTX and maybe the motherboard drivers.

What I can't help is this -> There are some very interesting settings we can set with the video drivers. Some skill may be needed by the owner to select which mode and if a DVD player, what setting does what. Microsoft (again) will not do this for us.

Best of luck,