Cannot play a video.......i need a software - Sony Walkman Video NWZ-A816 Digital Media Player

Are you referring to playing within a webpage or playing with a video player software? Each requires a different solution.

Upgrade your phone software version

connect phone to charger and then play video

If video continues to play and phone does not switch off then get batteries changed to get rid of the problem

if even now set switches off on playing videos probably your phone software is corrupt...(Even I phone s/w can get corrupt ) full reset your phone or get software reloaded.

Before doing this be sure u have latest version of software in your phone.

To play any media on PC needs codec to support it. If you are playing video on Windows Media Player, go to Tools - Options - then in opened dialogue of options go to DVD - Advanced . Here (Properties dialogue) you will find the supported codecs for different media. If the video file you are playing is not mentioned then the video won't play. So download the required codec to support the video file. A better option is install PowerDVD software which plays almost every video file. Download the old version software from the following link.
http://www.oldversion.com/download-PowerDVD-7.html
Name: Deluxe
Serial Key of Power dvd 7:
7GP2X-RWAWT-QMEQA-6EZ9U-GE356-W3VQD

Also install real player.

You don't need any software I guess. When you open media player in your phone, click option and see if there are any fullscreen setting in it.
Several phone with auto rorate even have easy way to make video played full screen. When we play video, just move the phone from portrait to lanscape mode, round 90 degrees, and the video will automatically full screen

If this helpful, RATE please !

download vlc player from internet.
It plays everything

Hi, You could view the video on the PC using the windows movie maker and a USB/ firewire cable connected to the camcorder.

can it do that?

my mobile not see the video