Creation of BuiltIn\Distributed COM Users group

I had installed Windows 2003 SP1 on one DC. I am following Microsoft Documentation for the same. Now I am stuck on the Distributed COM Users gruop. This is available in Builtin folder in AD. I had not configured any settings related to that till yet. I had upgraded the server to SP1 after words. Now I found that inside DCOMCNG a SID. This is a unresolved SID. So that created a doubt in m mind about the Builtin\Distributed COM Users group.

The SID that you mention belongs to DCOM user. And PDC creates that in AD. At the time of upgrading you get two ways to transfer the PCD role to the new upgraded system. You can go with current PDC or with PDC FSMO. So that depends on you. If you are having any other doubt then post the same in detail here.