What's MAC address ? What is a unique ID for a PC?

I have a PC with dual cores, it has two MAC addresses : 00-1D.... & 00-21..... Are these IDs for the two cores ? If I want to get hold of a unique ID for this PC, how to get it with a Java call ? Maybe there is something in Java like "System.getId()" ?

Frank

MAC stands for Media Access Control. The MAC address usually represents a unique id for your network adapter(s). You must have two network adapters in your pc (LAN, WLAN?).

Have a look here this describes how to get a unique system identifier in JAVA: How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

And .NET: http://sowkot.blogspot.com/2008/08/generating-unique-keyfinger-print-for.html

Michael

Edit

Adding the code in case the linked page gets deleted

using System;
using System.Management;
using System.Security.Cryptography;
using System.Security;
using System.Collections;
using System.Text;
namespace Security
{
/// <summary>
/// Generates a 16 byte Unique Identification code of a computer
/// Example: 4876-8DB5-EE85-69D3-FE52-8CF7-395D-2EA9
/// </summary>
public class FingerPrint
{
 private static string fingerPrint = string.Empty;
 public static string Value()
 {
     if (string.IsNullOrEmpty(fingerPrint))
     {
         fingerPrint = GetHash("CPU >> " + cpuId() + "\nBIOS >> " + biosId() + "\nBASE >> " + baseId()
                     //+"\nDISK >> "+ diskId() + "\nVIDEO >> " + videoId() +"\nMAC >> "+ macId()
                              );
     }
     return fingerPrint;
 }
 private static string GetHash(string s)
 {
     MD5 sec = new MD5CryptoServiceProvider();
     ASCIIEncoding enc = new ASCIIEncoding();
     byte[] bt = enc.GetBytes(s);
     return GetHexString(sec.ComputeHash(bt));
 }
 private static string GetHexString(byte[] bt)
 {
     string s = string.Empty;
     for (int i = 0; i < bt.Length; i++)
     {
         byte b = bt[i];
         int n, n1, n2;
         n = (int)b;
         n1 = n & 15;
         n2 = (n >> 4) & 15;
         if (n2 > 9)
             s += ((char)(n2 - 10 + (int)'A')).ToString();
         else
             s += n2.ToString();
         if (n1 > 9)
             s += ((char)(n1 - 10 + (int)'A')).ToString();
         else
             s += n1.ToString();
         if ((i + 1) != bt.Length && (i + 1) % 2 == 0) s += "-";
     }
     return s;
 }
 #region Original Device ID Getting Code
 //Return a hardware identifier
 private static string identifier(string wmiClass, string wmiProperty, string wmiMustBeTrue)
 {
     string result = "";
     System.Management.ManagementClass mc = new System.Management.ManagementClass(wmiClass);
     System.Management.ManagementObjectCollection moc = mc.GetInstances();
     foreach (System.Management.ManagementObject mo in moc)
     {
         if (mo[wmiMustBeTrue].ToString() == "True")
         {
             //Only get the first one
             if (result == "")
             {
                 try
                 {
                     result = mo[wmiProperty].ToString();
                     break;
                 }
                 catch
                 {
                 }
             }
         }
     }
     return result;
 }
 //Return a hardware identifier
 private static string identifier(string wmiClass, string wmiProperty)
 {
     string result = "";
     System.Management.ManagementClass mc = new System.Management.ManagementClass(wmiClass);
     System.Management.ManagementObjectCollection moc = mc.GetInstances();
     foreach (System.Management.ManagementObject mo in moc)
     {
         //Only get the first one
         if (result == "")
         {
             try
             {
                 result = mo[wmiProperty].ToString();
                 break;
             }
             catch
             {
             }
         }
     }
     return result;
 }
 private static string cpuId()
 {
     //Uses first CPU identifier available in order of preference
     //Don't get all identifiers, as very time consuming
     string retVal = identifier("Win32_Processor", "UniqueId");
     if (retVal == "") //If no UniqueID, use ProcessorID
     {
         retVal = identifier("Win32_Processor", "ProcessorId");
         if (retVal == "") //If no ProcessorId, use Name
         {
             retVal = identifier("Win32_Processor", "Name");
             if (retVal == "") //If no Name, use Manufacturer
             {
                 retVal = identifier("Win32_Processor", "Manufacturer");
             }
             //Add clock speed for extra security
             retVal += identifier("Win32_Processor", "MaxClockSpeed");
         }
     }
     return retVal;
 }
 //BIOS Identifier
 private static string biosId()
 {
     return identifier("Win32_BIOS", "Manufacturer")
     + identifier("Win32_BIOS", "SMBIOSBIOSVersion")
     + identifier("Win32_BIOS", "IdentificationCode")
     + identifier("Win32_BIOS", "SerialNumber")
     + identifier("Win32_BIOS", "ReleaseDate")
     + identifier("Win32_BIOS", "Version");
 }
 //Main physical hard drive ID
 private static string diskId()
 {
     return identifier("Win32_DiskDrive", "Model")
     + identifier("Win32_DiskDrive", "Manufacturer")
     + identifier("Win32_DiskDrive", "Signature")
     + identifier("Win32_DiskDrive", "TotalHeads");
 }
 //Motherboard ID
 private static string baseId()
 {
     return identifier("Win32_BaseBoard", "Model")
     + identifier("Win32_BaseBoard", "Manufacturer")
     + identifier("Win32_BaseBoard", "Name")
     + identifier("Win32_BaseBoard", "SerialNumber");
 }
 //Primary video controller ID
 private static string videoId()
 {
     return identifier("Win32_VideoController", "DriverVersion")
     + identifier("Win32_VideoController", "Name");
 }
 //First enabled network card ID
 private static string macId()
 {
     return identifier("Win32_NetworkAdapterConfiguration", "MACAddress", "IPEnabled");
 }
 #endregion
}
}