It looks like your Gw.dat file is corrupted, delete your old file and repair your installation then use the -image switch to get the updates. If this doesn't fix your problem, it's probably related to your drivers or video card although it really looks like a corrupted Gw.dat file realted problem.
Have you tried any other game to see if the problem was only with GW?
You can also try resetting your graphics settings to 'Default' to eliminate the glitching in the second picture. If that doesn't work and the problem persists its worth getting the Graphics Card checked out if its still in warranty. I don't mean to alarm you but that happened to my card as it approached death due to overheating so nip it in the bud if you can.
I'm using a rather old computer so my best bet would be to simply buy a new computer, I still need to see if its the .dat file thanks for the response!