Hello Rayhan. When Windows Search won't open in Windows 11, the next step is to try rebooting the search process. You can do this by opening Task Manager with Ctrl + Shift + Esc, moving over to the Details tab, finding SearchHost.exe, and ending the task. It should restart automatically and possibly fix the issue at hand. Then I would run the Search and Indexing troubleshooter available in Settings under System > Troubleshoot > Other troubleshooters. This is a built-in troubleshooter designed to detect search issues and apply fixes. If propelling the troubleshooter does not fix the search, it is worth trying another option of rebuilding the search index. You can find this option in Settings > Privacy & Security > Searching Windows. Once you find Searching Windows click on Advanced indexing options. In indexing options navigate to advanced, and select rebuild. When activated it takes some time to rebuild, but perhaps you will have search functionality again.
You can also restart the Windows Search service itself. You can do this by typing services.msc into the Run box (Win + R), then find Windows Search in the list and confirm that the startup type is Automatic. If it's not running, your option will say "Start" instead of "Stop", click "Start" to run the service. Then apply your changes. You can also go beyond that and keep going even further by repairing system files using the System File Checker and the DISM tools. You will start by running Command Prompt as administrator on your computer. Then run the following lines: sfc /scannow. Then run the command DISM /Online /Cleanup-Image /RestoreHealth. Running these commands may repair problems in the background that interfere with search behavior. If that still has not helped, you can reset Windows Search through PowerShell. Run PowerShell as admin. You will enter one simple command to re-register the ShellExperienceHost component and that will usually restore the damaged search functionality.
Here's the reference: Fix problem Search not working Windows report
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