Hi Alan. I'm Greg, here to help you with this.
If this would persist after a true Clean Install where all partitions are deleted off the drive, the latest bootable media is used, and was close to this gold standard Clean Install: http://answers.microsoft.com/en-us/windows/wiki... then it must be caused by something that is being added or modified.
It's important the latest version was used and all Updates (including Optional under Advanced) are installed because a known issue with terribly slow Explorer was fixed in April 2022 via an Update and is included in Version 22H2.
Next suspect is modifications, so try removing those to see if it is fixed. Next suspect is something else installed like an app, older program or Windows Update.
Did you happen to notice when this behavior began? Was it right after the reinstall or did it start later. Do you happen to have a System Restore point during that period which you can try to get back before the problem started, then monitor everything subsequently installed to try to isolate the problem?
If none of those apply or help then let's try the fixes for known issues of Windows 11 Explorer becoming slow:
https://helpdeskgeek.com/windows-11/how-to-fix-...
https://www.systweak.com/blogs/fix-file-explore...
https://www.reddit.com/r/Windows11/comments/q26...
https://www.reddit.com/r/Windows11/comments/v0r...
https://techviral.net/fix-slow-file-explorer-wi...
https://www.kapilarya.com/fix-windows-11-file-e...
https://nimbletech.org/slow-file-explorer-windo...
If none of those help Go over Windows 11 with this Performance Checklist to try to find and fix problems:
https://answers.microsoft.com/en-us/windows/for...
Feel free to ask back any questions. Based on the detailed results you post back, I will have other suggestions if necessary.
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