运行ThinkPHP 示例中心出现错误

运行ThinkPHP 示例中心的时候出现错误:
Warning: require(../../ThinkPHP/ThinkPHP.php) [function.require]: failed to open stream: No such file or directory in D:\wamp\www\Ajax\index.php on line 18
Fatal error: require() [function.require]: Failed opening required '../../ThinkPHP/ThinkPHP.php' (include_path='.;C:\php5\pear') in D:\wamp\www\Ajax\index.php on line 18

请问各位怎么解决呢？。

怎么没人帮忙呀