[Blindtlk] Fan Problem or something else?

[Marsha]

Hi
  I am wondering if someone can help me with this problem?
  I am using Windows XP.  When I go to some sites that have a lot of 
graphics, it doesn't matter if it is Firefox or IE8, the fan starts revving 
up.  It gets very much louder.  When these two thing happen, the entire 
computer bogs down.  Some times it becomes totally unusable, other times it 
can be salvaged.  If I restart the thing, the fan is quiet as usual.  Does 
anyone have a clue for this problem?  This often happens with streaming 
audio but isn't limited to it.  Thanks for any help you can give me.

Marsha