How to block file sharing from a specific machine?

I have a Win7 machine on a domain. File and print sharing is enabled and it has access to a large number of other networked machines. I wish to block all access to one specific machine on the network. I have a global rule in place that blocks all inbound and outbound traffic to the IP address of this machine for both TCP and UDP, yet when I open Windows Explorer and enter the name of this machine I am able to browse all the files there no problem, when I would expect (and require) that this access be blocked.

What am I doing wrong and how should I go about doing this correctly?

First you should block based on MAC address just encase the IP address changes for that machine, then make sure the block rules are above all other defined rules. Also block on IP protocol instead of just TCP/UDP. A simpler method would be to use the blocked network zone setting by going to firewall settings > Network zones > blocked zones > add new blocked address > type: MAC address and enter the MAC address of the machine you wish to block.