If the DAT file is a video, you can open it with its associated video app. However, if you aren't sure what app it's intended for, VLC Media Player should be able to open it as well.

You can turn on the Show Hidden Files option by going to File Explorer > View > Hidden Items. You'll see that there is not only an NTUSER.DAT file, but also one or several more with a LOG extension.

the .DAT file is the exact same as a .MPG file. if it's for home PC viewing, try re-encoding the file into DivX or ASF using a high bitrate and low keyframe intervals to maintain mpeg-like quality ...

I use notepad to open or edit .dat files associated with games. <P>Most official game sites want to sell you a book that will have the edit codes in them, but there's most likely a user site that ...