RE: Determining my PC's SID ?

From: jzhu (anonymous_at_discussions.microsoft.com)
Date: 04/30/04 

Date: Fri, 30 Apr 2004 07:51:05 -0700

Assuming that the computer is in W2K or later domain, the simplest way is to use Win32 LookupAccountName through interop. You need to append a "$" to the computer name for the lookup.

If you don't want to deal with interop, take a look at
http://www.datamarvel.com
It has most Win32 API, including LookupAccountName, exported. The following code will work:
        NET_SID sid = null;
        string domain = "";
        NET_SID_NAME_USE use = NET_SID_NAME_USE.SidTypeUnknown;
        NSid nsid;
        WinBase.LookupAccountName(null, "myDomain\\myComputer$", ref sid, ref domain, ref use);
        nsid = new NSid(sid); // For dumping SID in string.
        Console.WriteLine("Computer sid {0}, use {1}", nsid.StringSid, use);