iexplore.exe file insight

Just installed my new Norton Internet Security yesterday.  It keeps popping up with a file insight message saying that Internet Explorer is hogging my memory.  I am having trouble, particularly while running Yahoo Mail, with my page freezing for several minutes at a time, over and over.  It's driving me crazy and I'm worried about the performance of my computer.  What does this mean and how can it be fixed? 

 

Thanks so much!