Replace Section with ${MementoSection} and SectionEnd with ${MementoSectionEnd} for sections that whose state should be remembered by Memento.
For sections that should be unselected by default, use ${MementoSection}'s brother - ${MementoUnselectedSection}.
Sections that don't already have an identifier must be assigned one.
Section identifiers must stay the same across
${MementoUnselectedSection} [section_name] [section_index_output]
!include Memento.nsh
!define MEMENTO_REGISTRY_ROOT HKLM
!define MEMENTO_REGISTRY_KEY Software\Microsoft\Windows\CurrentVersion\Uninstall\MyProgram
Function .onInit
${MementoSectionRestore}
FunctionEnd
Function .onInstSuccess
${MementoSectionSave}
FunctionEnd
${MementoUnselectedSection} dinosaur sec_dinosaur
; some code...
${MementoSectionEnd}
${MementoSectionDone}
Written by kichik