Check if user is a member of the local admins group

IsAdmin.cs

public static bool IsAdmin()
{
    WindowsIdentity identity = WindowsIdentity.GetCurrent();
    WindowsPrincipal principal = new WindowsPrincipal(identity);
    if (!principal.IsInRole(WindowsBuiltInRole.Administrator))
    {
        return false;
    }
    else
    {
        return true;
    }
}