This is a quick sample code that I used quite often on customer sites:

1. To Check whether or not I am a local admin on my machine.
2. To quickly list what Windows groups my user account is part of.

To compile this code, you only need to:

• If you are using Visual Studio 2005 (or above):
  1. Create a “C# Console Appliation” project.
  2. Copy and paste the code below in “Program.cs”
  3. Check the target Runtime (.NET Framework 2.0 or above – it might work in earlier version, but I did not try).
  4. You only need to reference “System.dll”.
  5. Compile and run.
• If you are using the .NET SDK:
  1. Copy and paste the code into a “.cs” file
  2. Compile the code using the C# compiler (csc.exe). You only need to reference “System.dll”.
  3. Run it.

Here is the code sample (Program.cs – Renamed the file to “.cs”) :

using System.Security.Principal;

namespace AmIAdmin
{
 class Program
 {
 static void Main(string[] args)
 {
 WindowsIdentity wi = WindowsIdentity.GetCurrent();
 Display(@"Name", wi.Name);
 Display(@"Owner.AccountDomainSid", wi.Owner.AccountDomainSid.ToString());
 Display(@"User.AccountDomainSid", wi.User.AccountDomainSid.ToString());
 Display(@"IsAnonymous?", wi.IsAnonymous.ToString());
 Display(@"IsAuthenticated?", wi.IsAuthenticated.ToString());
 Display(@"IsGuest?", wi.IsGuest.ToString());
 Display(@"IsSystem?", wi.IsSystem.ToString());
 Display(@"");
 Display(@"IsIn 'BUILTIN\Users'?", IsInWindowsGroup(@"BUILTIN\Users", wi.Groups).ToString());
 Display(@"IsIn 'BUILTIN\Administrators'?", IsInWindowsGroup(@"BUILTIN\Administrators", wi.Groups).ToString());
 Display(@"");
 Display(@"Groups:");
 foreach (IdentityReference ir in wi.Groups)
 {
 NTAccount ntAcc = ir.Translate(typeof(NTAccount)) as NTAccount;
 string s = string.Format(@"'{0}' [{1}]", ntAcc.Value, ir.Value);
 Display(@"Group", s);
 }

 System.Console.Out.WriteLine();
 System.Console.Out.WriteLine(@"... Press Return ...");
 System.Console.In.ReadLine();
 }

 //static bool IsInWindowsGroup(WindowsBuiltInRole role, IdentityReferenceCollection groups)
 static bool IsInWindowsGroup(string role, IdentityReferenceCollection groups)
 {
 bool isInGroup = false;
 foreach (IdentityReference ir in groups)
 {
 NTAccount ntAcc = ir.Translate(typeof(NTAccount)) as NTAccount;
 if (role.CompareTo(ntAcc.Value) == 0)
 {
 isInGroup = true;
 break;
 }
 }
 return(isInGroup);
 }

 static void Display(string libelle, string msg)
 {
 string s = string.Format(@"{0}: {1}", libelle, msg);
 System.Console.Out.WriteLine(s);
 }

 static void Display(string msg)
 {
 System.Console.Out.WriteLine(msg);
 }
 }
}

P.S.

Here is the link (http://en.support.wordpress.com/code/posting-source-code/)  I used to correctly post sample code.