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

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If your PC opens the XLSB file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating XLSB file extensions with the wrong software program.