winmail.dat file cant be opened in windows media player

my .dat file is a video file but can’t open with windows media player I have Vista basic and the windows media player that came with it.
I have a Dell inspiron 531 PC it works very well however, my emails sometimes come with a winmail.dat attachment ,that's usually a video of some sort ,I Have tried to open it with other programs like real player and power point . what is a simple way to correct this problem?Thanks Suzonka

Last edited by Doctor Inferno on 28th March 2009, 12:17 pm; edited 2 times in total (Reason for editing : adding more information)

.dat extensions are usually files that are specific to a program. It is a wrapper used by Microsoft Outlook when sending certain attachments.

To open it you need to save the file and then use a TNEF extractor program to get the original files out.

Try this free software; Fentun to get the invoice out of your email. Download: http://www.fentun.com/

Alternatively, you can change the extension from .dat to whichever extension you know the original file was in.