Fixing Local Activation DCOM errors in the eventlog

I'm sure this has been covered elsewhere, but its been a while since I put anything here.

Every now and again you might find an annoying error popping up in the event logs like the following :

The application-specific permission settings do not grant Local Activation permission for the COM Server application with CLSID
{61738644-F196-11D0-9953-00C04FD919C1} to the user DOMAINusername SID.
This security permission can be modified using the Component Services administrative tool.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 

This just means that an application pool user does not have launch or activate permissions set for a specific component, or permissions are incorrectly set.

The first task is to track down which component is causing the error, and the easiest way is to take the CLSID and just search the registry for it.  The local service key will probably give you a decent idea of what it is, in the case of the above error it was the IIS Admin Service.

Next open up Component Services and drill down until you find the previously mentioned service.  If you open up the properties and view the security tab you should be able to click edit and modify the "Launch and Activation" permissions.  Add your missing user to this and ensure both "Local Launch" and "Local Activation" are both set, as "Local Launch" is the default permission.

Viola!