How to check if a given user is a member of the built-in Administrators group?

Question

I need to check programmatically (in .NET) whether a given user (domain account) is a member of the built-in Administrators group on a current computer (the one where the ap

Answer 1

You could loop the groups like i did in this answer:

Determining members of local groups via C#

After reading some more, the easiest thing would be to use the System.DirectoryServices.AccountManagement namespace. Here is how it can be used:

http://www.leastprivilege.com/SystemDirectoryServicesAccountManagement.aspx

Sample:

public static bool IsUserInGroup(string username, string groupname, ContextType type)
{
    PrincipalContext context = new PrincipalContext(type);

    UserPrincipal user = UserPrincipal.FindByIdentity(
        context,
        IdentityType.SamAccountName,
        username);
    GroupPrincipal group = GroupPrincipal.FindByIdentity(
        context, groupname);

    return user.IsMemberOf(group);
}