Computer not recognizing network/internet

I'm fixing up a friends computer because about a month ago, he had problems with connecting to the Internet. After reinstalling windows with updated driver, I still can not get the computer to recognize my network, even after configuring it for file sharing and assigning it a static IP. I can't even use the computer to directly connect to my DSL modem, while all the other computers in the house can do so just fine. The motherboard has built in Ethernet, and I do not have a PCI NIC to test out. What's the probability that the built in Ethernet is going haywire, and what can I do to fix it? Preferably without replacing the motherboard or buying a NIC. Thanks in advance for the help.

Here is the system's specs:

ASUS A7N8X-VM/400 Socket A
Anthlon XP 2000+
2X256 CORSAIR Value Select PC3200
WD 80GB HDD
Integrated Graphics
Windows XP Pro

 

If it's bad hardware, then you could get an external modem.

 

Hi whicky,

The modem's not the problem as I'm able to connect to the internet with my three computers and, and my router is working fine as well. I'm guessing that it's the built-in Ethernet port on the motherboard that's giving me problems, but I don't want to have to return the board under warranty and wait a few weeks for a replacement. I'm going to have to call ASUS and find out exactly how their process works.

 

It probably is the port itself; before you return the board and replace the NIC, why not try one of those old-fangled usb to ethernet adapters? If it's a port problem, you should be able to connect through the usb adapter, if you're having hardware issues, that may be a good indicator, since you don't have a PCI NIC or anything.