First, to install the .appx file you need the Installer and the operation system must be Windows 10.
When you have already downloaded the needed app, you should install the certificate for the app first.
You can find the certificate by following the next steps:
- Find the downloaded .appx file in folder
- Click on it with the right button of the mouse
- In the context menu select <Propreties>
- In the opened window go to the <Digital Signatures> tab
- Click on the file in the Signature list
- Click on the <Details> button
- Click <View Certificate> in the opened window
Now, when you found the certificate, do some easy actions to install it:
- In the opened window of certificate installation click <Install Certificate>
- Click the <Local Machine> radio button & Click <Next>
- In the "User Account Control" pop-up window click <Yes>
- In the opened "Certificate Import Wizard" window click the radio button next to the <Place all certificates in the following store>
- Click on the <Browse...> button
- In the pop-up window select the "Trusted People" folder & Click <OK>
- Click <Next> & <Finish>
- In the pop-up "Certificate Import Wizard" click <Ok>
- And click <Ok> in the istallation window
So, when the certificate is installed, only two simple steps left to install the application itself. Only click twice on the .appx file and click on the <Install> button.
Voila, the app has been successfully installed!