diff --git a/IPython/utils/_process_win32.py b/IPython/utils/_process_win32.py
index 0d899d4..f045920 100644
--- a/IPython/utils/_process_win32.py
+++ b/IPython/utils/_process_win32.py
@@ -83,7 +83,7 @@ def _find_cmd(cmd):
         path = None
         for ext in extensions:
             try:
-                path = SearchPath(PATH, cmd + ext)[0]
+                path = SearchPath(PATH, cmd, ext)[0]
             except:
                 pass
         if path is None: