diff --git a/development/Win32/packaging/installer/download.nsh b/development/Win32/packaging/installer/download.nsh
index d9641f4a8b..7e269145e3 100644
--- a/development/Win32/packaging/installer/download.nsh
+++ b/development/Win32/packaging/installer/download.nsh
@@ -155,15 +155,16 @@
   !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 3" "Text" "${DownloadLabel}"
   !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 4" "Text" "${HomeLabel}"
 
+
   ${if} ${ExePath} == ""
     !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 3" "State" "1"
     !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 4" "State" "0"
-    !insertmacro MUI_INSTALLOPTIONS_READ $0 "ioDownload.ini" "Field 5" "Flags"
-    !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 5" "Flags" $0|DISABLED
+    !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 5" "Flags" PATH_MUST_EXIST|DISABLED
     !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 5" "State" ""
   ${else}
     !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 3" "State" "0"
     !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 4" "State" "1"
+    !insertmacro MUI_INSTALLOPTIONS_WRITE "ioDownload.ini" "Field 5" "Flags" PATH_MUST_EXIST
 
     ${StrRep} "${ExePath}" "${ExePath}" "${RemoveFromPath}" ""
     StrCpy ${ExePath} "${ExePath}${AddtoPath}"
diff --git a/development/Win32/packaging/installer/ioDownload.ini b/development/Win32/packaging/installer/ioDownload.ini
index e5e3ddb0f1..3d568e93c2 100644
--- a/development/Win32/packaging/installer/ioDownload.ini
+++ b/development/Win32/packaging/installer/ioDownload.ini
@@ -39,4 +39,3 @@ Left=5
 Right=-1
 Top=47
 Bottom=58
-Flags=PATH_MUST_EXIST
\ No newline at end of file
diff --git a/development/Win32/packaging/installer/lyx_path_prefix.C b/development/Win32/packaging/installer/lyx_path_prefix.C
index 601818600b..5255183b6a 100644
--- a/development/Win32/packaging/installer/lyx_path_prefix.C
+++ b/development/Win32/packaging/installer/lyx_path_prefix.C
@@ -290,7 +290,9 @@ void __declspec(dllexport) run_configure(HWND hwndParent, int string_size, char
 		return;
 	}
 
-	std::string const command = std::string("start /WAIT /B sh.exe ") + configure_file;
+	// Even "start /WAIT /B sh.exe configure" returns
+	// before the script is done, so just invoke "sh" directly.
+	std::string const command = std::string("sh.exe ") + configure_file;
 	if (system(command.c_str()) != 0) {
 		pushstring("-1");
 		return;