Thread:Project:Support desk/Failed to open stream: Invalid argument (3)

PHP: 5.4.16 MediaWiki: 1.22.0 MySQL: 5.6.12

I have just copied MediaWiki to c:\wamp\www\wiki, and run through the configuration\install procedure. I saved LocalSettings.php to c:\wamp\www\wiki.

When I load http://localhost/wiki, I receive the following error:

( ! ) Warning: require_once(C:\wamp\www\wiki�xtensions\InputBox\InputBox.php): failed to open stream: Invalid argument in C:\wamp\www\wiki\LocalSettings.php on line 127

( ! ) Fatal error: require_once: Failed opening required 'C:\wamp\www\wiki\extensions\InputBox\InputBox.php' (include_path='.;C:\php\pear') in C:\wamp\www\wiki\LocalSettings.php on line 127

The folder C:\wamp\www\wiki\extensions\InputBox exists.

If I enter $MW_INSTALL_PATH = "C:\wamp\www\wiki"; \ in LocalSettings.php, I receive the error:

( ! ) Parse error: syntax error, unexpected 'require_once' (T_REQUIRE_ONCE) in C:\wamp\www\wiki\LocalSettings.php on line 127