Multimedia file is any audio/video file that you can play with Windows Media Player. You can find it in Windows 98 under Start/Programs/Accessories/Entertainment/Media Player. For best results and compatibility, we recommend you to install Active Movie. What multimedia files you can play depend on your hardware settings and software installed. For instance, it can be any sound, song, CD track (WAV, MID, MP3, CDA...) or movie (MPG, AVI, MOV...).