Uhhh, why? PowerPoint can already play the music when a specific slide is shown. All you have to do is tell it which file to play... Without writing a specific file system extension, you can't reliably monitor the file to see if it was opened by some other process. In order to get this to PARTIALLY work, you would have to constantly try and open the file exclusively, denying any shared access, just to see if the file was opened by some other process. If the file opens, no other process has it open. If it doesn't open, something else has it open. But, there are multiple problems with doing this: 1) You must try to open file, repeatedly, fast enough so that you don't miss the file being opened, read, and closed, in between your attempts to open the file. This will have the effect of degrading system performance and slowing down all other applications. 2) As explained in 1, you could easily miss a file being open, then closed. 3) If your monitor manages to open the file, you will automatically prevent any other app from opening that file. This will cause your presentation to stop or possibly crash altogether. RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
