For Acrobat Reader XI as of version 11.0.12 you will have to make a change in the reader's Read command in the registry, location:
HKEY_CLASSES_ROOT\AcroExch.Document.11\shell\Read\command
This is the original command:
"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe" "%1"
Close Acrobat Reader if it is opened and change the command into:
"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe" /A "navpanes=0" "%1"
Open a PDF document and the navpane should be hidden, and can be shown with the F4 key as before.