Spoof/Change MAC address in Vista

I found a nice tool to change your MAC address in windows vista, you may not know what a MAC address is so educate yourself here once you do that you can change your mac address in vista with an application called MACMakeup.

Download it here
I use it to change my ip address since my isp locks one ip per mac address I have. Some Cable Modem ISP's assign IP addresses base on the PC's MAC addresses. For whatever reason, if you need to swap 2 PC's regularly to connect to the cable modem, it would be a lot easier to change MACaddresses rather than to change Network Interface Card (NIC).

Here are some reasons you may need this...

Protect Personal and Individual Privacy. Some companies track users via their MAC Addresses. In addition, there are more and more Wi-Fi Wireless connections available these days, and Wireless network security and privacy is all about MAC Addresses.

Perform Security Vulnerability Testing, Penetration Testing on MAC Address based Authentication and Authorization Systems, i.e. Wireless Access Points. (Disclaimer: Authorization to perform these tests must be obtained from the system owner(s)

Build "TRUE" Stand-by (offline) systems with the EXACT same CompterName, IP, and MAC ADDRESSES as the Primary Systems. If Stand-by systems should be put online, NO arp table refresh is necessary, which eliminates extra downtime.

Some online Game Players (Gamers) require changing the MAC addresses to fix IP problems for some reason.

Build High-Availability solutions. For example, some firewalls that run on multi-port NIC's (i.e. quad port NIC) require the same MAC address for every port.

Troubleshoot Network problems. Arp Tables, Routering, Switching

Troubleshoot system problems

Test network management tools

Test incident response procedures on simulated network problems

Test Intrusion Detection Systems (IDS), whether they are Host and Network Based IDS.

If for whatever reason you need to keep the same MAC address as your old NIC, but your old NIC failed...

Some software can ONLY be installed and run on the systems with pre-defined MAC address in the license file. If you need to install one of these software to another system with a different Network Interface Card (NIC) because your NIC is broken

Some Cable Modem ISP's assign IP addresses base on the PC's MAC addresses. For whatever reason, if you need to swap 2 PC's regularly to connect to the cable modem, it would be a lot easier to change the MAC addresses rather than to change Network Interface Card (NIC). (You need to check with your ISP and make sure you are not violating any service agreements.)
If you want detailed information on this app go here