Error on Activation: Failed to open stream

This error occurs when I try to activate Custom Google Search:

Warning: include_once(D:\home\MYURL.com\wwwroot\me\wp-content\plugins\custom-google-search/widget.php): failed to open stream: No such file or directory in D:\home\MYURL.com\wwwroot\me\wp-content\plugins\custom-google-search\custom-google-search.php on line 27

Warning: include_once(): Failed opening 'D:\home\MYURL.com\wwwroot\me\wp-content\plugins\custom-google-search/widget.php' for inclusion (include_path='.;C:\php\pear') in D:\home\MYURL.com\wwwroot\me\wp-content\plugins\custom-google-search\custom-google-search.php on line 27