My ASUS 3GHz PC runs WinXP Pro/SP3 but its My Computer will only SHOW one optical disc drive at a time. That MAY be relevant to the PROBLEM I want to ask about. I have a DVD disc that I have used for YEARS to TEST whether a DVD player works - as it always quickly displays video in 'working' DVD players. In both DVD players of THIS PC, autorun presents an OPTION to play the disc in various players. If I choose Windows Media Player (series 9 is installed), I am told that "Windows Media Player is currently unable to play DVD video." and "A compatible DVD decoder is not installed."  Since the graphics card is for NVidea GForce 6200, I chose from the suggested option : NVidia DVD Decoder. That works (well) ONCE only. Connection to internet or otherwise makes no difference. I have tried this several times starting with identical clones. Why only ONE success, and after that, failure ? Real Player 11 and VLC do no better. Please clarify.
Does it behave better with only one DVD drive?
If so, that is the solution.