If you are wondering why the file has ‘NT’ in its name, it’s because this DAT file dates back to Windows NT. It was the first operating system to support multiple user profiles. Windows 98/95 did not ...

We keep getting e-mail attachments in winmail.dat files and can’t open them. What’s going on? Is there a utility that can extract the attachments from these? When Outlook or Outlook Express users send ...

.dat can mean many things. data of any type quite often ends up with these extensions. How about using the app that created them? You can also try viewing them in notepad.