Can Changing My MAC Address Prevent a DDoS Attack?
If you're curious whether or not changing your MAC address can prevent you from being assaulted by a DDoS attack (Distributed Denial of Service attack), then the answer is yes... but it mostly works on the short-term, and it's more about getting your ISP to change your IP address if you incidentally have a dynamic IP on hand (some Internet Protocol addresses are static, which means you cannot change them; consult your Internet Service Provider for more details in regards to the state of your IP). What does MAC addresses have to do with your IP? If you have a dynamic IP, your ISP goes about assigning you one in a random manner. Your MAC address corresponds to this IP address, so if you change your MAC, you change your IP.
What is a MAC address?
Every Internet connection is given a unique IP. The ISP determines the uniqueness of each connection based on your MAC address, which is in turn determined by your computer and its different parts. Your MAC address is alphanumeric, meaning it consists of A-F characters and the numbers 0-9. It is six pairs of numbers and characters, to be specific (e.g., 12-10-B3-D5-4D-67). You can alter this by going to your Control Panel and clicking Network Connections. Click on your Network Adapter, Properties, and Configure. Afterwards, click on your Advanced Tab and scroll down to "Network Address".
How to change the MAC address?
From there, you can change your MAC address one number at a time (e.g., from 12-10-B3-D5-4D-67 to 12-10-B3-D5-4D-68) or even the whole thing entirely (e.g., from 12-10-B3-D5-4D-67 to 87-16-E8-91-F2-1A). Regardless of how you change it (and as long as it accepts your changes, so it's best to play it safe and change only one number or letter of your address), it should result in your ISP assigning you a new IP address (which you can check out via sites like IPchicken.com). The idea here is to keep your DDoS attacker guessing what your new IP address is.
NIC MAC Address
If the MAC address change solution above isn't enough, then you can try to alter your MAC address of your NIC or Network Interface Card by going to your registry settings and doing it from there. You should open Control Panel again, go to Network and Internet, Network Connections, and search for the connection that's enabled and connected. Click that with your right mouse button and select Properties on the menu. The type of NIC you're using will be revealed, go to regedit and use that information to find the NIC and Network Address key value, modify it, enter your desired MAC address (without dashes or spaces).