if your pc opens the daa file, but it's the wrong application, you'll need to change your windows registry file association settings. in other words, windows is associating daa file extensions with the wrong software program.

How would the previous sentence be correctly capitalized?
If your PC opens the DAA file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating DAA file extensions with the wrong software program.