If the DAT file you're trying to open is text, you can convert the file into text in the Microsoft Excel program by first saving it as a CSV file.

Tips on opening a winmail.dat file, keeping seldom-used ink cartridges from drying out, and undoing an Undo.

Q. I received e-mail from a relative that says it is in a winmail.dat file. When I try to open the file, I get a message that says something like: "You are attempting to open a dat file. They are ...

What is the location of NTUSER.DAT file? Can you delete the NTUSER.DAT file? How does it work? This post answers all these questions and more.