Whenever I try to watch a video on my computer, the video starts, then pauses, then starts again (stop-and-go action), etc. throughout the whole video. It rarely does it when I watch a DVD movie, though it does happen occasionally. I have tried waiting a while for the buffering process to finish, but it doesn't help. I have WindowsXP Home Edition Service Pack2 with 2.52 GHz, 768 MB of RAM. Please help.