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

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