Improve Python launcher discovery docs

create_mezzanine.bat

@@ -1,8 +1,42 @@
 @echo off
-set "PYTHON_EXE=%LocalAppData%\Programs\Python\Python311\python.exe"
-if exist "%PYTHON_EXE%" (
-    "%PYTHON_EXE%" "%~dp0pvd_mezzanine.py" %*
-) else (
-    py -3 "%~dp0pvd_mezzanine.py" %*
+setlocal
+set "SCRIPT=%~dp0pvd_mezzanine.py"
+set "PYTHON_EXE="
+set "PYTHON_ARGS="
+
+for %%V in (313 312 311 310) do (
+    if not defined PYTHON_EXE if exist "%LocalAppData%\Programs\Python\Python%%V\python.exe" (
+        set "PYTHON_EXE=%LocalAppData%\Programs\Python\Python%%V\python.exe"
+    )
 )
+
+if not defined PYTHON_EXE (
+    where py.exe >nul 2>nul
+    if not errorlevel 1 (
+        set "PYTHON_EXE=py"
+        set "PYTHON_ARGS=-3"
+    )
+)
+
+if not defined PYTHON_EXE (
+    where python.exe >nul 2>nul
+    if not errorlevel 1 set "PYTHON_EXE=python"
+)
+
+if not defined PYTHON_EXE (
+    where python3.exe >nul 2>nul
+    if not errorlevel 1 set "PYTHON_EXE=python3"
+)
+
+if not defined PYTHON_EXE (
+    echo FEHLER: Python wurde nicht gefunden.
+    echo Bitte Python 3.10 oder neuer installieren:
+    echo https://www.python.org/downloads/windows/
+    echo.
+    echo Im Installer "Add python.exe to PATH", "py launcher" und "tcl/tk and IDLE" aktivieren.
+    pause
+    exit /b 1
+)
+
+"%PYTHON_EXE%" %PYTHON_ARGS% "%SCRIPT%" %*
 pause