diff -r ee074604bf0c PC/launcher.c
--- a/PC/launcher.c	Tue Feb 07 11:28:19 2017 +0300
+++ b/PC/launcher.c	Wed Feb 08 13:33:50 2017 +0000
@@ -130,13 +130,11 @@
 }
 
 #if defined(_WINDOWS)
-
 #define PYTHON_EXECUTABLE L"pythonw.exe"
-
+#define PYTHON_EXECUTABLE_BASE L"pythonw"
 #else
-
 #define PYTHON_EXECUTABLE L"python.exe"
-
+#define PYTHON_EXECUTABLE_BASE L"python"
 #endif
 
 #define MAX_VERSION_SIZE    4
@@ -1264,15 +1262,27 @@
                             error(RC_BAD_VIRTUAL_PATH, L"Unknown virtual \
 path '%ls'", command);
                         command += 6;   /* skip past "python" */
-                        if (search && ((*command == L'\0') || isspace(*command))) {
-                            /* Command is eligible for path search, and there
-                             * is no version specification.
-                             */
-                            debug(L"searching PATH for python executable\n");
-                            cmd = find_on_path(PYTHON_EXECUTABLE);
-                            debug(L"Python on path: %ls\n", cmd ? cmd->value : L"<not found>");
+                        if (*command && !validate_version(command))
+                            error(RC_BAD_VIRTUAL_PATH,
+                                  L"Invalid version specification: '%ls'.\n"
+                                  L"In the first line of the script, 'python' "
+                                  L"needs to be followed by a valid version "
+                                  L"specifier.\nPlease check the "
+                                  L"documentation.",
+                                  command);
+                        if (search) {
+                            /* Command is eligible for path search. */
+                            wchar_t name[BUFSIZE];
+                            _snwprintf_s(name, BUFSIZE, _TRUNCATE,
+                                L"%ls%ls.exe", PYTHON_EXECUTABLE_BASE, command);
+                            debug(L"searching PATH for python executable: "
+                                  L"%ls\n", name);
+                            cmd = find_on_path(name);
+                            debug(L"Python on path: %ls\n", cmd ? cmd->value :
+                                  L"<not found>");
                             if (cmd) {
-                                debug(L"located python on PATH: %ls\n", cmd->value);
+                                debug(L"located python on PATH: %ls\n",
+                                    cmd->value);
                                 invoke_child(cmd->value, suffix, cmdline);
                                 /* Exit here, as we have found the command */
                                 return;
@@ -1281,12 +1291,6 @@
                              * back to locating the correct installed python.
                              */
                         }
-                        if (*command && !validate_version(command))
-                            error(RC_BAD_VIRTUAL_PATH, L"Invalid version \
-specification: '%ls'.\nIn the first line of the script, 'python' needs to be \
-followed by a valid version specifier.\nPlease check the documentation.",
-                                  command);
-                        /* TODO could call validate_version(command) */
                         ip = locate_python(command, TRUE);
                         if (ip == NULL) {
                             error(RC_NO_PYTHON, L"Requested Python version \