あなたは.onSelChangeで好きなロジック強制することができます:
!include WinMessages.nsh
!include LogicLib.nsh
!include Sections.nsh
Page Components
Page InstFiles
InstType "Normal1"
!define CIT_Special 1
InstType "Special"
InstType "Normal2"
Section Foo
SectionIn 1 2 3
SectionEnd
Section Bar SEC_Special
SectionIn 1 3
SectionIn RO
SectionEnd
Section Baz
SectionIn 1 2 ;3 << Not the same as Foo just to have some sort of difference
SectionEnd
Function .onSelChange
;Normally you would call GetCurInstType here, but it seems we need a little hack to detect the custom section
FindWindow $1 "#32770" "" $HWNDPARENT
GetDlgItem $1 $1 0x3F9
SendMessage $1 ${CB_GETCURSEL} 0 0 $2
SendMessage $1 ${CB_GETITEMDATA} $2 0 $2
${If} $2 = ${CIT_Special}
!insertmacro UnselectSection ${SEC_Special}
${Else}
!insertmacro SelectSection ${SEC_Special}
${EndIf}
FunctionEnd
はGetCurInstTypeの動作は仕様です、それは必ずしもコンボボックスの選択と同じではありません、現在はInstTypeを返し判明します。 – Anders