To work around this issue, use one of the following methods.
Method 1: Shorten the UNC path and the file name
Shorten the UNC path and the file name of the movie that you inserted to fewer than 127 characters. To do this, move the movie to a higher folder level before you insert the movie into the PowerPoint slide presentation.
Method 2: Use Microsoft Windows Media Player
For more information about how to insert movies for Windows Media Player into your presentation, click the following article number to view the article in the Microsoft Knowledge Base:
299284
Add-in to insert movies using Windows Media Player is available for PowerPoint