xxxxxxxxxx
Open up regedit, go to HKEY_CLASSES_ROOT\CLSID\{0E270DAA-1BE6-48F2-AC49-3192CEBDF340}
Double-click System.IsPinnedToNameSpaceTree and change the value from 1 to 0.
close all open File Explorer windows and then open a new one
Note: Under \CLSID the content of {} might be slightly different.