Sideloading Apps

MS is great at providing general instructions. They aren't as good about covering the details.

One of the sticking points for me as I've been working on converting my desktop Win32 apps to list them on the Microsoft Store is how to sideload them so I can test them in Windows S mode. Well, I haven't solved that particular problem as of yet, because I haven't figured out how to sign the apps, but I did figure out how to sideload them in standard Windows 10 Home or Pro.

Here are the steps that work for me:

Load the Visual Studio solution that has your application and packaging projects. Double-click on Package.appxmanifest from your packaging project. Select the Packaging tab. Click Choose Certificate... and click View Full Certificate.

Select the Details tab and click on Copy to File..., which brings up the Certificate Export Wizard:

Exporting the certificate.

Click Next. You can select "No, do not export the private key" if you prefer, otherwise select "Yes, export the privacy key" and click Next:

Export the privacy key.

Accept the defaults on the Export File Format page and click Next:

Use the defaults.

You can set a password if you're exporting the private key. To do so, check Password, type in the same password in both fields, and click Next:

Set a password.

Provide a valid path and filename, then click Next:

Provide a path and filename to finish out the wizard.

This should save a .PFX file to disk.

If you need to create app packages for sideloading, you can do that by selecting the packaging project, opening the Project menu, selecting Store, then Create App Packages..., and selecting the Sideloading checkbox:

Create packages for sideloading.

Check the architectures you need to test with and click Create:

Select the architectures you need for your testing.

Now, install the .PFX file and the .MSIXBUNDLE package file.

To install the certificate, double-click the .PFX file to install it. Select Local Machine from the first page of the wizard, click Next, enter the password, click Next, select "Place all certificates in the following store", and click Browse. Select Trusted Root Certification Authorities and click OK. Click Next and then click Finish.

This should result in "The import was successful."

Now, double-click on the .MSIBUNDLE package file, click Install, and that's it! The application installs and launches automatically.

NOTE: You do have to have "Sideload apps" or "Developer mode" selected in "For developers" in the Windows 10 settings app for this to work:

Enable Sideloading.

Gary Lucero