The average Windows 8 user can only download apps that Microsoft has approved from the Windows Store. Windows 8 offers two ways to sideload unapproved apps, which are intended for developers and businesses with internal apps.
These methods cannot be used by the average geek to install unapproved apps from the web. Windows 8’s new interface takes the Apple iOS approach of forbidding unapproved software, not the Android approach of allowing all users to enable sideloading.
Note: This only applies to Modern apps in the new Windows 8 interface, not on the desktop. Windows desktop applications can be installed normally. However, you can’t install any desktop applications on devices running Windows RT.
Get a Developer License
Microsoft offers free developer licenses for Windows 8. These licenses allow developers to test and evaluate their apps before submitting them to the Windows Store. Each developer license license will expire after some time, but you can repeat the process to acquire a new license in the future.
Note that, according to Microsoft’s license agreement, these licenses may only be used for developing and testing your own applications. As Microsoft warns:
“Microsoft can detect fraudulent use of a developer license on a registered machine. If Microsoft detects fraudulent use or another violation of the software license terms, we might revoke your developer license.”
To acquire a developer license, first open Windows PowerShell as administrator. To do so, press Start, type PowerShell, right-click the PowerShell shortcut and select Run as administrator at the bottom of the screen.
Type the following command into the PowerShell window, press Enter, and agree to the license:
You’ll then have to provide Microsoft account details, which the developer license will be associated with.
After acquiring a developer license, you can run the following command in a PowerShell window to sideload a Modern application:
On a Domain
Windows 8 also offers a method for sideloading “line-of-business” apps. This allows businesses and other organizations to load apps onto their own computers without offering them publically through the Windows Store.
There are four requirements to sideload a line-of-business app:
You must be using Windows 8 Enterprise, Windows Server 2012, Windows 8 Pro, or Windows RT. If you’re using Windows 8 Pro or Windows RT, you’ll need to purchase a “sideloading product activation key” from Microsoft. Microsoft directs people interested in purchasing these keys to their Volume Licensing page.
If you’ve acquired a sideloading product key, you must open a Command Prompt window with administrator access and add it with the following command, where ##### is the 25-digit key:
slmgr /ipk #####
After adding the key, type the following command exactly to activate the sideloading key:
slmgr /ato ec67814b-30e6-4a50-bf7b-d55daf729d1e
Your computer must be joined to a domain to run the application. Even if you have Windows 8 Enterprise, you can’t install a line-of-business app unless your computer is on a domain. If you installed the application while joined to a domain, it will refuse to run unless your computer is connected to the domain.
You must enable sideloading in Group Policy. This setting can be enabled on your domain or on your local computer.
For example, to enable this option on your local computer, press the Windows key, type gpedit.msc, and press Enter. Navigate to the Computer Configuration\Administrative Templates\Windows Components\App Package Deployment folder in the Group Policy editor.
Double-click the Allow all trusted apps to install option and set it to Enabled.
The app must be signed with a key from a certificate authority that’s trusted on the local computer. For example, if you sign the app with a certificate from a trusted certificate authority such as Verisign, the app will install with no further configuration. If the app is signed with your own self-signed certificate, you’ll have to trust the self-signed certificate on the local computer.
If you’ve satisfied all the requirements, you can sideload Modern apps by running the following cmdlet in a PowerShell window:
There are a lot of myths about sideloading Modern apps on Windows 8 – for example, you can’t just enable a Group Policy setting. While developer licenses may seem like a possible loophole, Microsoft’s license agreement forbids using them for anything but app development. These licenses are also monitored and access to your apps could be revoked if you use it to sideload unapproved apps on your computer.