Please capitalize where necessary: if your pc opens the qlb file, but it's the wrong application, you'll need to change your windows registry file association settings. in other words, windows is associating qlb file extensions with the wrong software program.
If your PC opens the QLB file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating QLB file extensions with the wrong software program.