Disables search-engine indexing for all password-protected posts.
This plugin does one thing and one thing only. It adds the text
<meta name="robots" content="noindex"> to the header of any password-protected post. Google and all other respectable search engines will leave your password-protected pages out of their search results.
Extract the zip file and just drop the contents in the wp-content/plugins/ directory of your WordPress installation and then activate the plugin from plugins page.