Windows 10 apps are built and installed differently than traditional desktop applications. While with desktop applications, you need to go through various installation steps, with an appx package, you only need to click one button.
These types of apps (part of the Universal Windows Platform (UWP)) are usually available through the Microsoft Store, but there will be times when you’ll have to install them outside of the store.
Depending on how you acquired the app, you’ll come across apps with a digital signature, which is a requirement before they’re submitted to the Microsoft Store, and those that might still be under development and are unsigned.
While you can install digitally signed Windows 10 apps with a single click from the store and different sources, you cannot easily install unsigned apps. If you try to install an unsigned appx package, you’ll get the “Ask the app developer for a new app package. This one isn’t signed with a trusted certificate (0x800B0100)” error message. However, the installation isn’t impossible, you need to change the installation settings and use the PowerShell command-line tool.
This guide will teach you the steps to install unsigned Windows 10 apps on your computer.
Install unsigned appx packages on Windows 10
It’s important to note that in most cases, you shouldn’t install unsigned apps on Windows 10, as they may cause harm to your computer. However, if you are a developer or trying to install a new Windows 10 app outside of the store, you can use the following steps to install the unsigned “.appx” package.
Enable Developers mode
If the app doesn’t have a digital signature, you must enable the “Developer mode” on your computer.
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Open Settings.
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Click on Update & security.
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Click on For developers.
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Under the “Developer Mode” section, turn on the “Install apps from any source, including loose files” toggle switch.
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Click the Yes button.
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Restart your computer.
Once you have enabled the developer mode, you can install the unsigned packages.
Install unsigned apps using PowerShell
If you are trying to install an app that wasn’t packaged, meaning that you have a folder with all content instead of a single *.appx file, you will need to use the following instructions:
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Open Start, search for PowerShell, right-click the result, and select the Run as administrator option.
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Type the following command to register the app and press Enter:
Add-AppxPackage -Path PATH-TO-APPXFILEFOLDER\AppxManifest.xml -Register
If you have a “*.appx” file, double-click it, and click the Install button. Or to avoid running into any issues, you can use the following PowerShell command:
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Open Start.
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Search for PowerShell, right-click the result, and select the Run as administrator option.
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Type the following command to install the unsigned app and press Enter:
Add-AppxPackage -Path PATH-TO-APPXFILE\APP.appx
After you complete the steps, you can launch the app from the Start menu like any other Windows application.
Mauro Huculak is a Windows expert and the Editor-in-Chief who started Pureinfotech in 2010 as an independent online publication. He is also been a Windows Central contributor for nearly a decade. Mauro has over 12 years of experience writing comprehensive guides and creating professional videos about Windows, software, and related technologies, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and About.me.