windows - Why the error 404 happens when I access *.mp4 file by HTTP?

Question

I have some shared folder over HTTP. Lets say: http://myserver/files

And there are some filed like png, avi, jpg, mp4 and etc.

I can easily access *.png or *.avi via browser (http://myserver/files/555.avi) but cannot access to *.mp4.

So IIS gives the 404 error.

What's up?

Thank you!

UPDATES:

May be it is important: I have to access by this URL format

http://112.333.44.33/files/555.mp4

Answer 1

So I found the solution.

I just added correct MIME type to my website.

Extension: mp4

MIME type: video/mpeg

And now it works fine.