Hi,
Thank you for posting your issue to Microsoft Q&A forum.
From you screenshot, we could not see the value you have set for the registry key.
Please kindly check if you set as below:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Search\SearchboxTaskbarMode
Value data :
0 : hide
1 : search icon
2 : show
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\HideFileExt
0 = Show
1 = Hide
We also suggest that you could disable Cortana totally.
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search
“AllowCortana”=dword:00000000
For your reference:
https://social.technet.microsoft.com/Forums/ie/en-US/af677b8e-f30d-4fbc-a3b7-cd70c001c89f/windows-10-remove-cortanasearch-box-from-task-bar-via-gpo-for-osd?forum=win10itprosetup
https://appuals.com/remove-cortana-and-web-search-from-windows-10-taskbar/
https://shebangthedolphins.net/windows_grouppolicy_manage_searchbox.html
https://www.tenforums.com/tutorials/62842-hide-show-file-name-extensions-windows-10-a.html
Best regards,
If the Answer is helpful, please click "Accept Answer" and upvote it. Thanks.