How to change a MAC address in Microsoft Windows

Under Windows, the MAC address is stored in a registry key. To change a MAC address, find that key with `regedit` and change it. Of course, Microsoft keeps moving the location of the key around!

Windows XP adds an option to change the MAC address on some network cards under the Advanced tab in the network adapter's Properties menu.

A much easier and more reliable method to change a MAC address under Windows is to use a software utility program designed to do this for you.

Macshift is a free utility that you can use to spoof your MAC address under Microsoft Windows.
How to change a MAC address in MacOS





c. Remember the number between the long number (GUID) inside the { }. For example, in the above “net config rdr” output, for MAC address “00C095ECB793,” you should remember {1C9324AD-ADB7-4920-B02D-AB281838637A}. You can copy and paste it to the Notepad, that’s probably the easiest way. (See figure 2.)

d. Go to Start -> Run, type “regedt32” to start registry editor. Do not use “Regedit.”

e. Do a BACKUP of your registry in case you screw up the following steps. To do this

I. Click on “HKEY_LOCAL_MACHINE on Local Machine” sub-window

II. Click on the root key “HKEY_LOCAL_MACHINE”.

III. Click on the drop-down menu “Registry -> Save Subtree As” and save the backup registry in to a file. Keep this file in a safe place.

f. Go to “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}. Double click on it to expand the tree. The subkeys are 4-digit numbers, which represent particular network adapters. You should see it starts with 0000, then 0001, 0002, 0003 and so on. (See figure 3.)
g. Go through each subkey that starts with 0000. Click on 0000, check DriverDesc keyword on the right to see if that's the NIC you want to change the MAC address. The DriveDesc should match the Description you recorded from step (a.-I.). If you are not 100% sure about the DriverDesc, then you can verify by checking if the NetCfgInstanceID keyword value matches the GUID from step (c).
If there is no match, then move on to 0001, 0002, 0003, and so on, until you find the one you want. Usually 0000 contains the first NIC you installed on the computer.
In this demonstration, 0000 is the NIC I selected. (See figure 3.)

h. Once you selected the subkey (i.e. 0000), check if there is a keyword "NetworkAddress" exist in the right side of the window. (See figure 3.)

I. If "NetworkAddress" keyword does not exist, then create this new keyword:

i. Click on the drop down menu “Edit -> Add Value”.

ii. In the Add Value window, enter the following value then click OK. (See figure 4.)
Value Name: = NetworkAddress
Data Type: = REG_SZ

iii. String Editor window will pop up at this time (see figure 5.)

iv. Enter the new MAC address you want to modify. Then click OK.
(There should not be any "-" in this address. Your entry should only consist of 12 digits as seen in the figure 5.)

II. If "NetworkAddress" keyword exists, make sure it shows the keyword type is REG_SZ, and it should show as NetworkAddress:REG_SZ: . This keyword might not have a value at this time.

i. Double click on the keyword NetworkAddress and the String Editor window will pop up. (See Figure 5.)

ii. Enter the new MAC address you want to modify. Then click OK.
(There should not be any "-" in this address. Your entry should only consist of 12 digits as seen in the figure 5.)


j. There are 2 ways to make the new MAC address active. Method I does not require a system reboot:

I. Goto Start->Setting->Control Panel, and double click on "Network Neighborhood".
WARNING: Make sure you understand that you WILL lose the network connection after completing step "ii." below, and
if you have a DHCP client, you will get a new IP address after completing step "iii."

i. Select the Network Adaptor you just changed the MAC address.

ii. Right click on the selected Network Adaptor and click "Disable."
Verify the status column for this adaptor changes to "Disabled"

iii. Right click on the selected Network Adaptor and click "Enable."
Verify the status column for this adaptor changes to "Enabled"

iv. If for any reason it cannot be disabled or re-enabled, you have to
reboot your system to make the changes effective.

II. Reboot your Windows system.

k. Once completing step j (if rebooting the system, wait until the reboot is completed), go to command prompt, type “ipconfig /all” to confirm the new MAC address.



Restore The TRUE Hardware burned-in MAC Address:

1.

Remove the entry you added:

1.

If you followed Method 1, then go back to the advanced properties window and remove the entry you add.
2.

If you followed Method 2, then remove the "NetworkAddress" keyword you added in the registry.

2.

Use step (j) above to activate the change you make.
3.

Once rebooted, go to command prompt, type “ipconfig /all” to confirm the original MAC address.



If MAC Address changes does not work:

If for whatever reason the MAC address cannot be changed using method 2, make sure you restore the registry setting by following the "Restore The TRUE Hardware burned-in MAC Address" instruction above. If necessary, restore the registry you just backed-up to get your system back to the original state. You can do this by clicking on the drop-down menu “Registry->Restore,” and restore your backup registry file.


Instructions for changing the MAC address on a Macintosh can be found at MAC Spoofing on the Macintosh.
How to change a MAC address in FreeBSD

In FreeBSD, you can change your MAC address with the `ifconfig <interface> link <address>` command.
How to change a MAC address in Linux

Under Linux, you can change your MAC address with `ifconfig <interface> hw <class> <address>`, or you can use the GNU MAC Changer.
How to change a MAC address in Solaris

In Solaris, you can change the MAC address with the `ifconfig <interface> <ether> <address>` command.
How to change a MAC address in OpenBSD

OpenBSD does not, by default, allow you to change the MAC address. It is possible to change the MAC address under OpenBSD with sea.c.
How to change a MAC address in HP-UX

Under HP-UX, you can change the MAC address in SAM by selecting Networking and Communications, then selecting the interface, then Action, Modify, Advanced Options. HP-UX refers to the MAC address as the "station address".