The error message for the PIN related error reads- The error message for the Microsoft Store related error reads- We will be covering the fixes for each of the components separately so that there is no confusion.

Error Code 0x80090016 Microsoft Store

1] Sync Date and Time

You need to have a correct Date and Time set on your computer to access various Windows 11/10 services. For this, start by hitting the WINKEY + I button combinations on the keyboard to start the Settings app. Now, navigate to Time & Language > Date & time.

On the right side panel, turn the toggle On for Set time automatically and Set time zone automatically. Next, click on Region & language on the left side panel. Make sure that the Country or region on the right side panel is set to the country that you live in. Close the Settings app and Reboot your computer for the changes to take effect.

2] Re-register the Microsoft Store app using Powershell

Start by pressing WINKEY + X button combo or right-click on the Start button and click on Windows Powershell (Admin) or search for Powershell in the Cortana search box, right click on the Command Prompt icon and click on Run as Administrator. Click on Yes for the UAC or User Account Control prompt that you get. Then, the Windows Powershell window will finally be open. Now, type in the following command to re-register the Microsoft Store app and then hit Enter. Let the process complete and then check if your issue is fixed or not.

3] Reset the Microsoft Store

You can try to Reset Microsoft Store and check if any cached files or folders are causing a conflict to your Store being connected to the Microsoft Servers.

4] Run Microsoft Store Apps Troubleshooter

Microsoft has also released a dedicated Microsoft Store apps Troubleshooter. You need to download and run it.

Error Code 0x80090016 for PIN

The cause behind the issue is the corruption of the contents of the NGC folder. The NGC folder is responsible for storing certain files which are crucial for the system’s security. The most probable reason behind the corruption of the folder is when a third-party software modifies the files. Other than this, third-party software products induce certain background processes which could cause this error. We will proceed with the solutions in the following sequence:

1] Uninstall any recently installed third-party software

Usually, freeware products aren’t always free. Such products come along with extensions and other malware. If you have installed any such software recently, please uninstall them from the Control Panel. Even in case of genuine software, the third-party product could induce processes that cause this error in turn. You could consider uninstalling any such software, even if temporarily.

2] Empty contents of NGC Folder

First, boot Windows 10 into Safe Mode. You need to delete all the contents of the NGC Folder – for that you will need to take ownership of this folder first- Once done, just permanently delete all the contents of that folder and reboot your computer normally. The AppData folder might be hidden so you may need to show hidden files & folders.

3] Use Group Policy Editor

Hit the WINKEY + R button combination to launch the Run utility, type in gpedit.msc and hit Enter. Once Group Policy Editor opens, navigate to the following setting-

Now, on the right side panel and double click on Turn on convenience PIN Sign-in and set the radio button to Enabled for it.

This will turn on the Logins using PIN. Setting the radio button as Disabled or Not Configured will turn off the Logins using PIN. Exit the Group Policy Editor and then reboot your computer for the changes to take effect.

What is error code 0x80090016?

Error code 0x80090016 may appear in two different locations – while using Microsoft Store and while changing the PIN. Depending upon the situation, you can solve the issue by following the aforementioned steps. For example, you can synchronize date and time, reregister the Microsoft Store app, reset the Microsoft Store app, etc.

Why does Microsoft keep saying my PIN is incorrect?

There could be two reasons why Microsoft Store keeps saying the PIN is incorrect. First, there could be a bug preventing the Microsoft Store from validating the PIN. Second, your administrator has changed the PIN recently.  You need to follow the above-mentioned guides based on why and when you get the error. Hope this helped!