Can't watch video clips

I just purchased a new LG Lcd monitor, now I can’t watch video clips but there is sound. I have always used ATI File Player with my crt monitor with no problems. I tried opening the video clips windows media player, still no picture, just sound. I have a ATI ALL-IN-WONDER 9000 Pro video card. I have connected my monitor to my computer via DVI-D cable.
Thanks for all your help!! :iagree:

Run dxdiag, also check that overlay is enabled and the needed codecs are installed.

Ran windows update found a new driver for my monitor & video card, and now it works!

                                                                          Thanks Again, Great Site!!!!!