"My internet set up is kinda weird so I will try to explain it:
My computer -> dLan plug -> Router -> Phone Line
Parents computer -> Router -> Phone line
"
why do you think its weard ?
the Atheros AR8121 is a generic 1 gig ethernet chipset/SOC what exactly is this "dlan plug" you speak of ?
do you actually mean a generic wired ethernet cable pluged into your onboard ethernet socket at one end and the other into the routers lan port 1, i assume so....
right, as far as the internal LAN your connected to is concerned, the thing thats changed is YOUR MAC No.
the router above you refer to, is not giving out a DHCP IP address after getting a request from you, or your PCs not picking up the response....
is the router locked down to only give access to the old MAC No.s and if so thats simple, unlock it, then it should let you connect, then add your new MAC no. to the list and set it back to secure...
the problem IS between your ethernet port and the router, nothing after than can effect you as you deal with that router for all your input/ouput routing..... so concentrate your efforts there if the info you have given is accurate....
you removed the MAC address so i cant be sure, but in the case of a direct connection to the VM CM its been known that a generic MAC of 00.00.00.00 on a wired ethernet PCi card can stop the DHCP server giving out a valid IP address, but it works fine for a USB2 ethernet with the same generic MAC address, but iv never seen it, or had any reports that it can also happen with a 3rd party routers DHCP server before..... but werth keeping in mind.
the solution for that old VM bug was simple, put another MAC address in your windows ethernet stack registry overrideing the default 00.00.00.00 and the connected DHCP server will then give you a valid IP, netmask, default gateway, and DNS server ip address for the network.
that may work for you too...even if this is a 3rd party routers HDCPd
what is that EXACT routers make, model, and firmware No. BTW, a direct URL to its page might enlighten us perhaps.