Warning: Constant WP_USE_THEMES already defined in D:\www\www917\wp-includes\compat.php on line 645

Warning: require(D:\www\www917\wp-includes/wp-blog-header.php): Failed to open stream: No such file or directory in D:\www\www917\wp-includes\compat.php on line 648

Fatal error: Uncaught Error: Failed opening required 'D:\www\www917\wp-includes/wp-blog-header.php' (include_path='.;C:\php\pear') in D:\www\www917\wp-includes\compat.php:648
Stack trace:
#0 D:\www\www917\wp-settings.php(34): require()
#1 D:\www\www917\wp-config.php(103): require_once('...')
#2 D:\www\www917\wp-load.php(50): require_once('...')
#3 D:\www\www917\wp-blog-header.php(13): require_once('...')
#4 D:\www\www917\index.php(17): require('...')
#5 {main}
  thrown in D:\www\www917\wp-includes\compat.php on line 648