Keep tools panel closed on open

Hi,

Honestly, the best quickest solution is to open a PDF in Read Mode  (hit Ctrl+H keys), OR, just close the Tools Pane, then close Acrobat .

The next time that you open PDFs the Tools Pane, it will (and should) stay closed due to Adobe Acrobat being able to remeber its last documents' View state.

Even though this is not a permanent solution, it seems that when you close your document, Acrobat will remember the last view settings.

However, to permanently disable this behavior, the best solutions that I could find (and tried myself successfully) are found in the two links below: 

1. https://helpx.adobe.com/acrobat/kb/how-to-permanently-close-the-tools-pane-in-adobe-acrobat-dc.html
2. https://superuser.com/questions/902758/remove-or-prevent-sidebar-from-opening-by-default-on-adobe-reader/918966#918966

If you choose option 2, when you navigate to " C:\Program Files (x86)\Adobe\Acrobat DC\Acrobat\AcroApp\ENU" you have to open the " Viewer.aapp " in  a text editor, such as Notepad, in Administrator mode.

The directory to which this file writes itself to can only be editable as an Administrator and not with your regular user account  profile. 

Also, by modifying  the Viewer.aapp  XML file you will notice that if you go back to the registry key indicated above in the solution offered by Adobe through option 1, the key "  bExpandRHPinViewer " is deleted from the registry path " [HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat\DC\AVGeneral] ".

So if you're not experienced with editing/modifying  XML files nor messing around with Windows registry settings, then it is safer to go with option 1, just like Adobe suggests and  assign a "0" value to the key..

However, it is possible that when new updates are applied on Acrobat (or any other unnoticed system event(s)),   you may notice that Acrobat/Reader could revert back to opening the tools pane automatically again.

If this is something really annoying to you, then you can delete the  bExpandRHPinViewer key, OR   when you open Viewer.aapp in Notepad, delete this whole part from the XML file:

	<Layouts>
		<Layout name="Default" rhpModes="expanded,appSwitcherOnly">
			<RHP>
				<Component name="AppShortcutListView" type="Custom"/>
			</RHP>
		</Layout>
	</Layouts>
</Application>

and only leave this part:

<Application xmlns="http://ns.adobe.com/acrobat/app/2014" title="Viewer" id="Viewer" majorVersion="1" requiresDoc="true" minorVersion="0">

and Save and close the file.

You  will NOT be bothered anymore by the Tools Pane everytime you open a PDF.