I see in the archives that this has been reported before, and I can verify that the attached patch does fix the problem for me. Basically what is happening is that the launcher is trying to execute python with the "#!" still in the name. I verified this by rebuilding gui.exe without -mwindows arg so it would still be a console app so I would see the failure message. It printed this: "Could not exec #!c:\TOOLS\python25\pythonw.exe" -- Robin Dunn Software Craftsman http://wxPython.org Java give you jitters? Relax with wxPython! Index: launcher.c =================================================================== --- launcher.c (revision 59634) +++ launcher.c (working copy) @@ -231,8 +231,8 @@ if (is_gui) { /* Use exec, we don't need to wait for the GUI to finish */ - execv(python, (const char * const *)(newargs)); - return fail("Could not exec %s", python); /* shouldn't get here! */ + execv(ptr, (const char * const *)(newargs)); + return fail("Could not exec %s", ptr); /* shouldn't get here! */ } /* We *do* need to wait for a CLI to finish, so use spawn */