diff --git a/bin/dxfs2lib.bat b/bin/dxfs2lib.bat
index 14cdf5a..d0d1935 100644
--- a/bin/dxfs2lib.bat
+++ b/bin/dxfs2lib.bat
@@ -7,4 +7,4 @@ REM Beispielaufruf mit Parametern:
 REM --in: Ordner mit .dxf-Dateien (optional. Standard: work/converted_dxfs)
 REM --name: Name der zu erzeugenden Bibliothek
 
-python %PROJECT_LIB%\dxf2lib.py %*
\ No newline at end of file
+"%VIRTUAL_ENV%\Scripts\python.exe" %PROJECT_LIB%\dxf2lib.py %*
diff --git a/bin/manage_interpreter.bat b/bin/manage_interpreter.bat
index 02d47a3..1b061e1 100644
--- a/bin/manage_interpreter.bat
+++ b/bin/manage_interpreter.bat
@@ -1,30 +1,33 @@
 @echo off
 CALL setenv.bat
-IF DEFINED NETWORK_INTERPRETER_PATH (
-    goto %~1_network
 
+IF /I "%1"=="activate" GOTO activate
+IF /I "%1"=="deactivate" GOTO deactivate
+GOTO :eof
+
+
+:activate
+REM Interpreter wählen
+IF DEFINED NETWORK_PYTHON (
+    SET PYTHON_EXE=%NETWORK_PYTHON%\python.exe
 ) ELSE (
-    goto %~1_local
+    SET PYTHON_EXE=python
 )
 
-:activate_interpreter_local
-IF NOT EXIST %PROJECT%\.venv CALL %PROJECT_BIN%\install_py.bat
-CALL %PROJECT%\.venv\Scripts\activate.bat
-goto :eof
+REM venv sicherstellen
+IF NOT EXIST "%PROJECT%\.venv" (
+    "%PYTHON_EXE%" -m venv "%PROJECT%\.venv"
+)
 
-:deactivate_interpreter_local
-deactivate
-goto :eof
+REM venv aktivieren
+CALL "%PROJECT%\.venv\Scripts\activate.bat"
 
-:activate_interpreter_network
-SET OLD_PATH=%PATH%
-SET PATH=%NETWORK_INTERPRETER_PATH%;%PATH%
-CALL %PROJECT%\.venv\Scripts\activate.bat
-goto :eof
+REM Interpreter festnageln
+SET VIRTUAL_ENV_PYTHON=%PYTHON_EXE%
+GOTO :eof
 
-:deactivate_interpreter_network
-SET PATH=%OLD_PATH%
-SET OLD_PATH=
-SET NETWORK_INTERPRETER_PATH=
-CALL %PROJECT%\.venv\Scripts\deactivate.bat
-goto :eof
+
+:deactivate
+CALL "%PROJECT%\.venv\Scripts\deactivate.bat"
+SET VIRTUAL_ENV_PYTHON=
+GOTO :eofecho off
diff --git a/bin/plant2dxf.bat b/bin/plant2dxf.bat
index 4e590e7..6e518f0 100644
--- a/bin/plant2dxf.bat
+++ b/bin/plant2dxf.bat
@@ -1,4 +1,6 @@
 @echo off
 CALL manage_interpreter.bat activate_interpreter
-python %PROJECT_LIB%\plant2dxf.py %*
+cd /d %PROJECT%
+"%VIRTUAL_ENV%\Scripts\python.exe" -m lib.plant2dxf %*
 CALL manage_interpreter.bat deactivate_interpreter
+exit /b %ERRORLEVEL%
diff --git a/bin/run_unittests.bat b/bin/run_unittests.bat
index 9bf0d3b..55e24e8 100644
--- a/bin/run_unittests.bat
+++ b/bin/run_unittests.bat
@@ -12,8 +12,8 @@ if %ERRORLEVEL% NEQ 0 (
     pause
     exit /B 1
 )
-
-python -m unittest discover -t %PROJECT_LIB% -s lib\Elemente -p "*_tests.py" -v
+echo python -m unittest discover -t %PROJECT_LIB% -s %PROJECT_LIB%\Elemente -p "*_tests.py" -v
+"%VIRTUAL_ENV%\Scripts\python.exe" -m unittest discover -t %PROJECT_LIB% -s %PROJECT_LIB%\Elemente -p "*_tests.py" -v
 if %ERRORLEVEL% NEQ 0 (
     echo.
     echo Tests failed!
diff --git a/bin/setenv.bat b/bin/setenv.bat
index 1a2ec6c..0af194e 100644
--- a/bin/setenv.bat
+++ b/bin/setenv.bat
@@ -19,6 +19,7 @@ if not exist %PROJECT%\log mkdir %PROJECT%\log
 if not exist %PROJECT%\testdata mkdir %PROJECT%\testdata
 
 set PATH=%PROJECT_BIN%;%PATH%
+REM set NETWORK_PYTHON=TO_BE_SET
 
 
 popd