Windows XP lets you change the physical address of a network card.
The network interface card installed inside your computer includes a unique physical address called the MAC (media access control) address. While the MAC address is intended to be stationary, it is possible to manually change the address in the Windows XP operating system. There are two different ways to modify the physical address through the operating system. Changing the MAC address requires either modifying an option in the Control Panel or manually changing a registry entry.
Instructions
Control Panel
1. Access the Windows XP Start menu and navigate to the Control Panel. Double-click the "Network and Dial-up Connections" icon.
2. Right-click the entry for your computer's network card and select "Properties." Navigate to the "General" tab.
3. Click "Configure" and navigate to the "Advanced" tab. Click the "Network Address" option underneath the "Property" heading.
4. Type a new 12-digit MAC address, without using any dashes or colons, in the "Value" text box. Click "OK."
5. Restart the Windows XP operating system.
Registry Editor
6. Open the Start menu and click "Run." Type "CMD" and tap "Enter." Type "ipconfig /all" in the command prompt window and tap "Enter." Note down the current MAC address listed in the "Physical Address" field. Type "net config rdr" and tap "Enter."
7. Locate the long string of numbers inside the opening "{" and closing "}" characters. Note down the string of numbers and close the command prompt.
8. Return to the "Run" window and type "regedt32." Tap "Enter." Click the folder labeled "HKEY_LOCAL_MACHINE." Navigate through the folders named "SYSTEM," "CurrentControlSet," "Control" and "Class."
9. Click the subfolder with the same name as the string of characters you noted earlier. Open the first subfolder named "0000." Check the "Network Address" value at the right side of the screen and see if it matches the physical address you noted earlier.
10. Open the next subfolders until you find the folder with the matching Network Address entry. Double-click the entry and type the new MAC address you want to use in the text box. Restart the computer.
Tags: Control Panel, Network Address, operating system, command prompt, earlier Open, network card