diff --git a/lib.sh b/lib.sh
index 820641d..bdb8897 100644
--- a/lib.sh
+++ b/lib.sh
@@ -2,24 +2,26 @@
 
 # 
 lib_get_esptool_command() {
+    WIN_PYTHON="py.exe"
     if command -v esptool.py &> /dev/null
     then
         echo "esptool.py"
     else
-    if ! command -v py.exe &> /dev/null
+    if ! command -v $WIN_PYTHON &> /dev/null
         then
-            echo "esptool.py nor py.exe could not be found. Please install it first."
+            echo "esptool.py nor $WIN_PYTHON could not be found. Please install it first."
             exit 1
         fi
         # check if esptool is installed as a module
         if py.exe -m esptool --help &> /dev/null
         then
-            echo "py.exe -m esptool"
+            echo "$WIN_PYTHON -m esptool"
+            return
         else
             echo "install esptool module for python first."
-            py.exe -m pip install esptool
+            $WIN_PYTHON -m pip install esptool
         fi
-        echo "py.exe -m esptool"
+        echo "$WIN_PYTHON -m esptool"
     fi
 }