--- a/toolkit/mozapps/installer/windows/nsis/common.nsh
+++ b/toolkit/mozapps/installer/windows/nsis/common.nsh
@@ -5087,20 +5087,21 @@
             ${If} $R8 == "false"
               StrCpy $AddStartMenuSC "0"
             ${Else}
               StrCpy $AddStartMenuSC "1"
             ${EndIf}
 
             ; We still accept the plural version for backwards compatibility,
             ; but the singular version takes priority.
+            ClearErrors
             ReadINIStr $R8 $R7 "Install" "StartMenuShortcut"
             ${If} $R8 == "false"
               StrCpy $AddStartMenuSC "0"
-            ${Else}
+            ${ElseIfNot} ${Errors}
               StrCpy $AddStartMenuSC "1"
             ${EndIf}
 
             ReadINIStr $R8 $R7 "Install" "TaskbarShortcut"
             ${If} $R8 == "false"
               StrCpy $AddTaskbarSC "0"
             ${Else}
               StrCpy $AddTaskbarSC "1"