You can open .DAT files that contain text, with text editors, like Notepad, Notepad++, VS Code, etc. But it is not possible to know what contains in a DAT file.

Though DAT files, which house data as the shortened name implies, are usually best left alone, here's how you can open them.

How to Open a DAT File in Word. File extensions usually tell your computer something about a particular file and how to open it. For instance, when the computer encounters a DOCX file, it will use ...

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.

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.