If the Photos app does not start or causes an error, you can repair it using PowerShell. Here are the steps for Windows 10.

Click Start, type powershell, right-click Windows Powershell and choose Run as Administrator

To re-register or reinstall the Photos app, use one of the following methods:

Option 1

Execute the following command:

Get-AppxPackage -allusers Microsoft.Windows.Photos | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

Option 2

First, run the following command to get the Package ID of Photos App and then use it in the 2nd command below:

Get-AppxPackage Microsoft.Windows.Photos -allusers | select PackageFullName

Note down the Package name shown. For example, if the Package name is listed as Microsoft.Windows.Photos_16.302.8200.0_x64__8wekyb3d8bbwe, execute the next command as follows:

Add-AppxPackage -register "C:\Program Files\WindowsApps\Microsoft.Windows.Photos_16.302.8200.0_x64__8wekyb3d8bbwe\AppxManifest.xml" -DisableDevelopmentMode

This reinstalls the Photos App.

Another option to install Photos is to download it from Windows Store.

Open Windows Store from Start/Search.

In the Store App, search for Microsoft Photos and install it.

Uninstalling Photos app

Type the following command and press {ENTER}

Get-AppxPackage Microsoft.Windows.Photos | Remove-AppxPackage

This uninstalls the Photos App.