I had a very strange issue when setting up a DHCP reservation on my router. Whilst attempting the setup my Windows 7 computer was reporting one MAC address (both under ipconfig & through a program called Change MAC Address) and my router was reporting another (and NO there weren't other wireless devices connected to the router which I was not aware of!).
I Googled the subject, naturally, and didn't come up with much - however by shear luck I did stumble across a solution - this is what I did!
1). Opened a command prompt
2). Typed "arp -a" (minus the double talking marks) and hit enter
3). Opened Control Panel --> Network & Sharing Center --> Change Adaptor Settings
4). Right clicked on Wi-Fi Adapter & selected properties
5). Double clicked "Internet Protocol Version 4 (TCP/IPv4)"
*** At this point another Properties dialog box opens ***
6). Clicked on OK (didn't change any of the values!)
7). Clicked on OK (again didn't change any values!)
8). Ran the "arp -a" command again
9). Rebooted the Wireless Router & the computer
I did attempt various reboot combinations with the Wireless Router and the laptop before running the "arp -a" command as stated above, however these efforts didn't prove fruitful.
I hope that this helps somebody else out there on the web.