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I will be glad to help you with the issue you have with the computer. I understand the frustration when things don't work the way it should.
Please follow the below steps to know how to uninstall Photo App in Windows 10:
- Close the Photos app if you currently have it open
- In the the Cortana/Search Windows box type powershell
- Click on ‘Windows PowerShell’ when it appears – right click on it and choose ‘Run as Administrator’
- In the PowerShell window enter the following command (tip: copy and paste will save mistakes.
Get-AppxPackage *photo* | Remove-AppxPackage
A ‘Deployment operation progress …’ message will temporarily appear. When this goes the uninstall has finished.
The Photos app will now be gone and the Windows Photo Viewer will now be used to open your images.
Hope this information is helpful. Please post in case you have any further issues, we are happy to help you further.