explorer.exe error

hello. I have a problem with my computer. Everytime I highlight a video file, there is an error with explorer.exe. I do not have to open the video file, just highlight it. I get an error randomly, too. Sometimes I’ll click on several before I get an error, sometimes I get an error as soon as I highlight one. When I do, I get the “Do you want to send an error report?” window. The video files are all .wmv, .avi, .mpg, etc. There are no Real or Quicktime files. Anybody have a clue as to what’s happening? This error just popped up unexpectedly. I have not installed anything recently. My system:
AMD Athlon XP 800 mhz
384 mb RAM
FIC AZ11 motherboard
onboard sound (AC ’97)
GeForce FX5200
Directx 9.0