Hi @Neudisld,
Depending on the exact steps you took to insert audio and/or video into your PowerPoint presentation, you may have ended up creating essentially links to the audio/video files on your own computer instead of having that info embedded within the powerpoint. That would be one reason everything would work for you (you have access to all of the files) but not your teacher (they have the powerpoint you uploaded, but not all of the other files it may be referring to).
If you're allowed to submit a video instead of a .ppt file, i'd honestly save your powerpoint as an MP4 and then submit that. Doing that *should* create one video file of your presentation which would include your audio and videos, and would be viewable by your instructor. If your videos are long, this may create a rather large file that may take a while to upload though, so do look out for that.
I hope this info helps!
-Chris