Laptop freezing when playing videos

[Atlantean]

My laptop recently started freezing whenever playing movies, any movies... dvd, avi, rm etc. I am not really sure why it is doing this and the entire thing just freezes, it will play the video fine for a while and then the system will just freeze up. Everything else seems to work fine and I don't really want to have to reformat the disk to make video work again. Any ideas as to what could be causing the problem? Only software I recently added is psp video 9, so that I could convert movies to play on my psp. Problem still occurred after I uninstalled the program.