USB Thumb Drive Video AutoPlay

I have configured my WD TV Live unit for automatic video playing and looping of the video.  I am having problems when I insert certain USB thumb drives into the WD TV Live.  I copy only one media file - an MP4 file onto the drive, have the WD TV Live powered off, and power it on after inserting it.  With one of my thumb drives, it always works fine.  I have two others that I copy the same file to, and they won’t autoplay.  Any suggestions … thanks.

Tech Support helped me … each usb device has to be configured to autoplay, so once I did that problem solved.

Configured how?