C# string.GetHashCode() returns non int result

One of my clients had an app crash and i traced it due to this bug/feature i can't really explain.
The WindowsIdentity.GetCurrent().Name.GetHashCode() returns this string: - ?2097695743
Yes, that a minus, a space, a question mark and then the actual hash numbers.

This is the code of a simple console app that show the weird behaviour.

static void Main(string[] args)
{
    Console.WriteLine("From String: string name = WindowsIdentity.GetCurrent().Name");            
    string name = WindowsIdentity.GetCurrent().Name;
    Console.WriteLine("name:                            " + name);
    Console.WriteLine("name.GetHashCode().GetType():    " + name.GetHashCode().GetType());
    Console.WriteLine("name.GetHashCode():              " + name.GetHashCode());
    Console.WriteLine("name.GetHashCode().ToString():   " + name.GetHashCode().ToString());
    Console.WriteLine();
    Console.WriteLine();
    Console.WriteLine("Direct");
    Console.WriteLine("WindowsIdentity.GetCurrent().Name:                           " + WindowsIdentity.GetCurrent().Name);
    Console.WriteLine("WindowsIdentity.GetCurrent().Name.GetHashCode().GetType():   " + WindowsIdentity.GetCurrent().Name.GetHashCode().GetType());
    Console.WriteLine("WindowsIdentity.GetCurrent().Name.GetHashCode():             " + WindowsIdentity.GetCurrent().Name.GetHashCode());
    Console.WriteLine("WindowsIdentity.GetCurrent().Name.GetHashCode().ToString():  " + WindowsIdentity.GetCurrent().Name.GetHashCode().ToString());
    Console.WriteLine();
    Console.WriteLine();
    Console.WriteLine("Press Enter to continue");
    Console.ReadLine();
}

This is the text output:

From String: string name = WindowsIdentity.GetCurrent().Name
name:                            COMMARC\tje
name.GetHashCode().GetType():    System.Int32
name.GetHashCode():              - ?2097695743
name.GetHashCode().ToString():   - ?2097695743

Direct
WindowsIdentity.GetCurrent().Name:                           COMMARC\tje
WindowsIdentity.GetCurrent().Name.GetHashCode().GetType():   System.Int32
WindowsIdentity.GetCurrent().Name.GetHashCode():             - ?2097695743
WindowsIdentity.GetCurrent().Name.GetHashCode().ToString():  - ?2097695743


Press Enter to continue

And this is a picture of the same output:

My question is: How on earth is this possible?

UPDATE: the problem was with the funky windows settings for negative numbers.