Everyone has a fear of criminal hackers. They are every where and looking to invade your PC. They can park a block away from your home, break into your wireless network and gain access to your PC. What you don't know is they can access your PC twenty four hours a day, even when it is off. What the hacker does is send a unique wake-up call to your wireless network that contains the MAC address of your PC.
The MAC(Media Access Control) address is the hardware address located within the Ethernet adapter in your PC. This unique hexadecimal code allows your PC to communicate to other hardware on the network without an IP(Internet Protocol Address) . When your PC first connects to a router's DHCP and queries it for a new IP only the MAC address is used to communicate with that system. When ever you logon to a wireless network your PC transmits your MAC address and the name of your PC on that network. At an airport, in a restaurant, wherever you access the internet, personal information about your machine is transmitted over the air waves. To increase your privacy I recommend you change your computer's name periodically and spoof the MAC address to mask th e hardware address and prevent criminals from turning your PC on remotely.
You may change your computer's name by right clicking on My-Computer and selecting properties. You will see the computer name tab on that dialog. I recommend giving your PC a generic name such as Anonymous, DELPC or something generic that can not easily be tracked. Change this value at least once every six months for any laptop you own.
Spoofing the MAC address is not as easy but I highly recommend you do this to every PC you own. Once the MAC address has been spoofed the permanent hardware MAC will be hidden from hackers. The spoofed address can not be used to turn your PC on.
To spoof your PC's MAC address do the following: Right click on the icon "My Network Places" and select Properties. A dialog will open showing one or more of your network connections. If you are using a laptop you may see two connections labeled "Local Area Connection" and "Wireless Network Connection". These names may very from PC to PC but they are similar in how they work. Right click on the network connection you use most and select "Properties" on that dialog select "Configure" The configuration dialog for that hardware will then be displayed. Select the Advanced tab and click on "Network Address" If the "Not Present" radio button is selected this means your default hardware address has been exposed to any network you have connected to. You can spoof this value by selecting the Value radio button and entering a random number in the edit box. This value must start with two zeros and be twelve digits long. You may use any digit from 0-9 and the letters A-F in this field. After you have made the changes select OK then reboot your PC. You may download a program to do this for you at the following link http://www.bruceraisley.com/MacSpoof.zip .