I don't know your skill level with networking, but forgive me in advance if I go over the super obvious to you.
Things you should know:
- DHCP - The protocol used by your router to give your devices automatic IP addresses.
- Static IP - IP addresses assigned to certain devices that never change
You could mean two things regarding "MAC address access list"
1.) MAC address filtering - Only computers with certain MACs are allowed to connect to your network. All unidentified MACs not on that list are denied access to your network.
2.) DHCP IP reservation - Certain IP addresses are reserved for particular MAC address. For example, 00:11:22:33:44 will always be 192.168.0.100
Assuming you are using MAC address filtering (#1), there are two possibilities that I see...
A.) The MAC address for your laptop is incorrect, disabled or not working as intended for some reason. Causes include a typo, using your *wired* network card MAC address instead of your wireless network card MAC address, a router firmware bug (not working as intended) or that MAC address is somehow not whitelisted (read: disabled or not enabled).
B.) Your laptop's IP address has been manually set on the computer as a static IP which always stays the same.
If you are actually using MAC addresses to assign static IPs through DHCP (#2), then consider these things...
A.) You have assigned two different MACs the same IP address in your router configuration
B.) You have mistakenly assigned a static IP to your laptop's MAC which was already in use by another device.. perhaps already given out by DHCP or even assigned manually on the device itself. In this case, make sure each IP reservation is unique.
C.) You have used MAC-based DHCP reservation to assign a static IP to your laptop's MAC address... which falls within the router's DHCP range. Example: 00:11:22:33:44 has been assigned an address of 192.168.0.100. A badly designed router may allow you to also have it configured in such a way that it gives out IP addresses starting at 192.168.0.100 via DHCP. Due to numerous reasons, it is possible that 192.168.0.100 was given to another device before you connected with your laptop, ultimately causing an IP conflict. Restarting your router, updating the firmware or changing the the DHCP range so they do not overlap could fix this problem.
D.) Your laptop's IP address has been set as a static IP on the laptop itself, in which case it ignores the information it gets from the router in regards to what IPs are in use. Make sure your laptop is set to lease an automatic DHCP address.
Some more information could be valuable here -- What brand/model of router do you have? What's your current IP address? Is it DHCP or static? How many other computers do you have on your network? Are you connecting wirelessly or using a cable? When did this start happening? Did it ever work properly? Have you tried any troubleshooting steps like ipconfig /release, restarting equipment etc..?
The more info you can provide, the more likely it is we'll be able to narrow down your issue.