The VideoLAN Forums

Hi, I'm here to ask if it's possible to play a .part file without having downloaded the first part of it.
Thank you

In most cases weird archives must be assembled before they can be viewed.

http://www.videolan.org/vlc/features.html
Supported Formats

Generally, if you have the beginning, you can play all the parts that you have, but without the beginning, you are dommed, because it contains all the file descriptor.