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 Multiple CSV Files in One Excel Spreadsheet. The CSV file extension appears on text documents that contain comma-separated values. Like spreadsheet data, each line in a CSV file ...

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 ...