C# Check if run as administrator [duplicate]

Try this

public static bool IsAdministrator()
{
    var identity = WindowsIdentity.GetCurrent();
    var principal = new WindowsPrincipal(identity);
    return principal.IsInRole(WindowsBuiltInRole.Administrator);
}

This looks functionally the same as your code, but the above is working for me…

doing it functionally, (without unnecessary temp variables) …

public static bool IsAdministrator()
{
   return (new WindowsPrincipal(WindowsIdentity.GetCurrent()))
             .IsInRole(WindowsBuiltInRole.Administrator);
}  

or, using expression-bodied property:

public static bool IsAdministrator =>
   new WindowsPrincipal(WindowsIdentity.GetCurrent())
       .IsInRole(WindowsBuiltInRole.Administrator);