Right-click the DAT file on your PC and click "Open." Click "Select a program from a list of installed programs" and click "OK". Click "Microsoft Excel" from the list of programs on your computer.

How to open a .csv file in Excel Opening a .csv file is as easy as opening a .txt file, and usually, you won’t have to clean up the data before doing so because the save task inserts the delimiter.

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