A few years ago, she had a problem with frequent system freezes or crashes which were tracked down to "the wrong video card driver". Supposedly technician replaced the video driver and this was fixed, and she had not been a problem for 2 years. Recently she started to experience her computer display freezing up again -- most frequently when she was reading her Yahoo email in IE, though not exclusively in that situation, and not every time she viewed her email. She believe this has to do with the video driver because after each freeze, she would reboot, and when IE would start up it would report that an error had occurred due to a "wrong video driver". She believed this problem started shortly after Yahoo changed their email page and began running video ads on it, though this is could just be a coincidence.
This happens with some regularity, like once per week, but is not something we can repeat on demand yet.
Any thoughts on how to diagnose this problem further and how to repair it?