I’m just starting out in Blender, going through the Noob to Pro tutorial, but already I can see that the Box and Circle select tool are messed up in that they ghost completely. That is, for instance, with the circle select tool, it looks like I’m in a paint program and dragging around the screen with a circle brush… everywhere it goes, it remains, until I leave the tool completely. Same thing happens for the box tool, and I haven’t used Blender enough yet to know what else.
Sounds like a Video Card problem. Try different settings in Display Properties on your OS like Color Quality and Hardware Acceleration. If that doesn’t work find a Driver that works. If your card has its own settings turn off AntiAliasing. Make sure you don’t have Shadows or Trails on in Mouse settings.