The windows file explorer comes with OneDrive and Shortcuts attached to the left-hand side of the window. There is no easy way to remove it, so you have to make changes to the registry.
win-r - open the run commandregedit to the opened windowComputer/HKEY_CLASSES_ROOT/CLSID/018D5C66-4533-4307-9B53-224DE2ED1FE6System.isPinnedToNameSpaceTree to 0Of course you can change it back to 1 to reenable it.
win-r - open the run commandregedit to the opened windowComputer/HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/ExplorerHubMode and set its value to 0Of course you can change it back to 1 or just remove the entry to reenable it.