Just spotted this bit of Info over at Rojakpot.com

Whenever I click or open certain AVI movies in Windows XP, Windows Explorer would lock up and cause the entire system to come to a standstill. You also cannot edit or delete these AVI movies! Why? Why? Why???! Because this is yet another Windows XP bug. Don't take it the wrong way. I love Windows XP. It's the most stable Windows OS ever. But this bug sure has bugged me (pun intended!) long enough! It's time to fix it once and for all!