You can not insert MIDI files into PowerPoint presentations directly. After doing this you will get "PowerPoint cannot insert a sound from the selected file. Verify that the path and file format are correct, and then try again." message in PowerPoint 2003 or "Run-time error '429': ActiveX component can't create object." in PowerPoint 2007.
Microsoft offers a workarounds for different PowerPoint versions, but you will get error message when you view a presentation that has embedded sounds in PowerPoint 2003 or in PowerPoint 2007 on another computer.
What can we do? All PowerPoint versions starting from 2000 supports WAV file embedding without any limitations. So, we need to convert MIDI file into WAV format and insert it in presentation. But how we can convert MIDI to WAV? MIDI to WAV converter lets you make this job quick and easy. Download and install converter, add your MIDI files, select WAV output format and click the "Convert" button. Also, you can convert MIDI to WMA format to reduce file size.