There are occasions which some of us may experience during or shortly after the upgrade of a Dynamics CRM 4.0 system to CRM 2011 where we discover we have plugins that cannot be removed by the Plugin Registration Tool.
Most of the time this is caused by the plugin being registered as "on disk" and it not being available to the CRM 2011 server, in some way.
Regardless, there are cases where the Plugin Registration Tool simply will not unregister the assembly because it "can’t find it."
Kill Plugin uses the SDK to delete the plugin and its associated steps.
Visit the Codeplex site here:
You may download a zip file containing everything required to run the tool (via the command-line) or you can download the source and build your own copy.
I have tested it in a limited set of environments so if you have any issues, please let me know.