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

If you're having trouble opening a DAT file, I'll show you a simple and free way to do it. This method works on both Mac and PC. Just open your browser and go to winmaildat.com. It's a ...

Index.dat file reader or viewer You can use freeware Index.dat Suite or Index.dat Scanner to view the index.dat file in Windows 7 or earlier. But you will not be able to use these freeware on ...

Change Association This Time Sometimes you may want to open a data file with a different program. To open a file by choosing the application, see Win Open With.

Q. I sometimes receive e-mail messages with a “winmail.dat” file attached that I cannot open. Why does this happen, and what can I do to fix it? A. The winmail.dat file usually appears because ...

If you double-click a file and it opens in the wrong program, try this: In Windows’ File Explorer, right-click a file with the extension you have in mind, and select Open with.