URL rewrite - friendly URL

Hello, I'm having some problems with the URL rewrite module.

I've followed the instructions given  here, and it works on localhost, but when I copy this code:

<rule name="RedirectUserFriendlyURL1" stopProcessing="true"><match url="^$" /><conditions><add input="{REQUEST_METHOD}" pattern="^POST$" negate="true" /><add input="{QUERY_STRING}" pattern="^([^=&amp;]+)=([^=&amp;]+)$" /></conditions><action type="Redirect" url="/{C:1}/{C:2}" appendQueryString="false" /></rule><rule name="RewriteUserFriendlyURL1" stopProcessing="true"><match url="^/([^/]+)/([^/]+)/?$" /><action type="Rewrite" url="?{R:1}={R:2}" /></rule>

which was generated by the module, I get a 404 response from my server.

The URL in the browser does change from http://example.com/?cat=music tohttp://example.com/cat/music, but the same error always occurs.

Why is that, isn't this just a simple "query formatting", so to speak.