Isp Comcast network issue

[Djharlock]

I am struggling to fix this issue, I have no idea what the problem could be so I am posting the issue here to see if I can get some help.

Recently got comcast Digital TV and Highspeed, took a while to hook up internet, modem wouldn't be recognized or connect when I used Ethernet cable, used 3 different cables just incase, used Usb cable and finally connected. Internet running subpar 128kb/s download rate. I tried hooking up a router to use multiple connections ( I have vontage) and send out a wireless signal) didn't work. I had a tipoff it might be the modem, so I exchanged it for a different one at local comcast. When I tried to hook it up it does not run on either ethernet and usb It wants me to create a new account but I have one so shouldn't I have a connection already cause I installed it on pc? It doesn't recognize my modem after I installed drivers but their site came up on internet explorer but I had a connection cause I could ping sites ex. google on cmd promt then I tried to see if I could get ethernet to run so I went to network connections and saw a LAN connection for where my ethernet was connected but I couldnt get on internet. I did something now I can't even pick up the comcast block page thing, it gives the infamous IE error page and my computer created a 2nd connection I guess for modem but it says limited or no connectivity and when I run the installer it sees the modem but no connection. It is all hooked up correctly and my tv still get's signal so what is wrong?

[johnwill]

Whenever you change the modem on a Comcast account, they have to register the MAC address of the new modem, so it's essentually a "new" connection. Contact Comcast tech support and explain your situation, they should be able to take the MAC address from the modem label and enable your account.