If you’re on Windows 10,8.1 or 8, and you try to install the apps from Store, you may get this error saying Something happened and this app couldn’t be installed. Please try again. Error code: 0x80073cf9
You’re not alone. Many Windows users are reporting it. But the good news is you can fix it. Go on with the easy solution below.
Note: The screens shown below are from Windows 10, but all the fixes also apply to Windows 8 too.
Please click the solution according to your Windows operating system.
For Windows 8 users: Restore AUInstallAgent directory in the Windows Folder
For Windows 10/8.1 users: Restore AppReadiness directory in the Windows Folder
For Windows 8 users: Restore AUInstallAgent directory in the Windows Folder
0x80073cf9 could be probably caused by the missing AUInstallAgent directory in your Windows 8.
To restore it:
1) On your keyboard, press the Windows logo key 
and E at the same time to invoke the File Explorer window.
2) Go to This PC > Local Disk (C:) > Windows.
3) Right-click on the blank area to click New, then Folder.
4) Click Yes when prompted by User Account Control.
5) Name the new folder: AUInstallAgent.
6) Reboot your Windows 8. Then go to the Windows App Store to install the app again to see if it’s successful.
For Windows 10/8.1 users: Restore AppReadiness directory in the Windows Folder
0x80073cf9 could be probably caused by the missing AppReadiness directory in your Windows 10 or 8.1.
To restore it:
1) On your keyboard, press the Windows logo key and E at the same time to invoke the File Explorer window.
2) Go to This PC > Local Disk (C:) > Windows.
3) Right-click on the blank area to click New, then Folder.
4) Click Yes when prompted by User Account Control.
5) Name the new folder: AppReadiness.
6) Reboot your Windows 10/8.1. Then go to the Windows App Store to install the app again to see if it’s successful.
