Motherboard problems... HELP PLEASE!!!!!!!

I just finished my first build and there are a couple things wrong with the motherboard. I have a Biostar TA770 A2+ http://www.newegg.com/Product/Prod [...] 6813138102

1.) I can only get 2 RAM slots to work, i have 4 GB installed now but I had wanted to install 8GB but it doesn't work, it won't even boot. I know that all of the sticks work because I tried them individually.
http://www.newegg.com/Product/Prod [...] 6820227199

2.) For some reason my Ethernet port doesn't work either. I don't know if this is because my internet provider (Comcast) won't accept two computers trying to use the same modem or what. I removed the Ethernet cable from my old computer and connected it to my new one and tried to use the installation disk that came from Comcast to setup my internet connection and it said that there was no device detected. I hooked it back up to my old computer and it works fine. I just have the modem that Comcast gives you for the self install.

The RAM isn't as big of a deal because Windows XP is only recognizing 3.25GB of the 4GB that is installed anyway so it won't recognize anymore anyway, I don't think anyway.

The Ethernet thing is a little more of a problem. I kind of need the internet lol.

Any information would be very helpful, thank you

i got the internet up and running on my new motherboard, i just didn't install it the way Comcast would like me to, with their software disk.

thanks for the reply