Error 797 when trying to set up wired connection in Windows 7

I'm trying to set up a wired connection with my brand new Dell XPS 8700 PC (running Windows 7 SP1). I was able to set up a wireless connection just fine, but I want to use a wired connection.

Unfortunately, I've been completely unsuccessful in doing this. For a while, I would always encounter a message saying "Error 651" when I tried setting up the connection, but now I'm constantly getting "Error 797".

I called my ISP, and the tech I talked to speculated that there might be a problem with the port I was using and advised me to call Dell. However, the Dell tech I talked to said it was most likely a driver problem.

I've tried:
-Replacing raspppoe.sys
-Turning off Windows auto-tuning
-Uninstalling the network driver and restarting
-Running System Restore
-Downloading and installing a new network driver
-Disabling TCP/IPv6

So far, nothing's helped, and I feel like I'm running out of options here (not to mention, feeling completely out of my depth). If anyone here can give me any advice, I would greatly appreciate it.

Thanks in advance!

Sysinfo:
(Also, my computer connects to a Netgear CG3000D router, which then connects to an Arris TM602G modem. I used this same setup to establish a wired connection on my old computer (a Gateway DX200X running Windows XP SP3), so I doubt there's any problem with that hardware.)