Check and Correct the System’s Date and Time Settings

1. Open the Settings app on your Windows device. You can do this by clicking on the Start menu and selecting the gear icon, or using the Windows + I keyboard shortcut.
2. Click on “Time & language.” In the right-hand menu, select “Date & time.”
3. Check the date and time and adjust them as needed. If the Time & date options are greyed out, toggle the Set time automatically option off.

Use the Windows Store Apps Troubleshooter

1. Open the Settings app on your Windows device. You can do this by clicking on the Start menu and selecting the gear icon, or using the Windows + I keyboard shortcut.
2. Click on “System.” In the right-hand menu, select “Troubleshoot.”
3. Click on “Other troubleshooters.”
4. Scroll down and click the Run button next to the  “Windows Store Apps” troubleshooter.
5. The troubleshooter will begin scanning your system for any issues with Windows Store apps. Follow any on-screen instructions to resolve any issues found.
6. Once the troubleshooter is finished, restart your device to ensure that any changes made take effect.

Reset the Microsoft Store and its Components

1. Open the Windows Search bar and type in the word PowerShell. From the search results, highlight the Windows PowerShell application, and click Run as Administrator.
2. When prompted by the User Account Control (UAC), click Yes to allow the app to launch with administrative permissions.
3. Copy and paste any of the following command, and then press Enter to execute it: WSReset.exe
4. Allow the command to run and reset your Microsoft Store components. After it’s finished, you may need to restart your computer for the changes to take effect.

Disable Proxy Settings

1. Open the search bar in your taskbar by clicking on the magnifying glass icon. You can also bring it up with the Windows + S keyboard shortcut.
2. Type in “Internet Options” and click on the first search result.
3. Switch to the Connections tab once the pop-up window shows up, and then click on LAN Settings.
4. Once in the Local Area Network (LAN) Settings window, make sure that the “Use a proxy server for your LAN” option is not enabled. If the option is enabled, simply click on the checkbox once to make it empty.
5. After disabling the proxy server, click OK and restart your computer.

Enable Microsoft Account Sign-in Assistant Service

1. Press the Windows + R keys on your keyboard. This is going to bring up the Run utility.
2. Type in “regedit” without quotation marks and press the Enter key on your keyboard. This will launch the Registry Editor application.
3. Use the navigation pane on the left side of the window to reach the following Registry key, or use the address bar and copy-paste the location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PolicyManager\current\device\Accounts
4. Locate the “AllowMicrosoftAccountSignInAssistant” key in the right-side panel and double-click it.
5. Change the Value data to 1 and press the OK button.

Switch to a Different User Account

Try accessing Microsoft Store from a different user account to see if the “PUR-AuthenticationFailure” error still persists. If the error is due to a corrupt user profile, create a new account and sign in to see if the problem has been resolved.