Windows Media Player must be the default application for playing .mpg files. If RealPlayer or QuickTime are used to open .mpg files, change the file association back to Windows Media Player. The Windows Help section on your computer has instructions on how
to change associations for file extensions.
Be sure the correct CD-ROM for the lesson is in the workstation. If video is located on the network, be sure workstations have access to that location.
If workstations with zip drives display an error message “No disk in drive” before playing the video, you may need to change certain settings on each workstation.
Some systems may have software that conflicts with ModuMath ability to play video in the lessons. One documented problem is with Sonic Cinema Player Decoder Package which is bundled with Roxio CD burning utilities. The conflict can be resolved
by uninstalling the Decoder Package via the Windows Control Panel.