If you didn't receive a drivers or resource CD / DVD with your system them unfortunately the best way to get the drivers is to download them to another system and copy them over using a USB drive or something similar.
Here is a link to the downloads page for the Latitude E6430. It defaulted to Windows 7 64-bit version for me but make sure you check the operating system filter on the downloads page when you pull it up to make sure. To help me better troubleshoot this issue please right click on my Dell Todd username and send me a private message with the Dell Service Tag of your Latitude E6430. Please keep all troubleshooting discussions here on this public thread so that others can see what we discuss.
I received your PM but you didn't include your service tag in the message. Here is a direct link to the Windows 7 Intel 825xx 10/100/1000 Ethernet Controller Driver, which is for your integrated (wired) network card. What happens when you copy that file onto a flash drive and try to install it into your E6430? Are there any specific error messages that come up?
You may also want to try to download the Intel Device Manager Diagnostics Utility and run that to see if there are any problems with the network card itself.