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.

To make Notepad files always open in a new or separate window in Windows 11, open Notepad setting and change the 'Opening files' option.

Need to use third-party programs to open files on your PC? Here's how to change file associations in Windows 10 and choose which apps open which file types.

I need to open up 4 text files at a time all with the same name but with different extensions. I've created a very simple batch file to take care of this using notepad, but it will only open up ...