My uncle asked me to troubleshoot his computer over the phone: He had viruses, he deleted a bunch of files, and now internet doesn't work (although he said that was before the file deletion). He then proceeded to un-install the lan drivers, to see if it helped. It didn't, and that's when he called.
Appart from the fact that there are obviously software/driver problems, one of the things he told me intrigued me. He said that when looking behind his computer at the ethernet port (and connected cable), that there were no lights at all. Looking at his switch, the port dedicated to the PC also "had no light", although the one used by his laptop was green with flashing orange.
I asked him to make sure they were correctly connected, and to try another cable, and he gets the same result.
Before making him jump through loops (I'm on the phone, so it's rather combursome procedures), to reinstal drivers, configure stuff etc. I just wanted know. Does the complete lack of connection lights on the motherboard port and swictch ports necessarally indicate a hardware connection problem? or can bad drivers create this symptom?
I wanted to edit but I can't:
Edit: I realized I didn't even say it: The problem is, under XP "a network cable is unplugged", even though it is, so it's not an internet connection problem per say, but really just an ethernet connection problem.
Does the complete lack of connection lights on the motherboard port and swictch ports necessarally indicate a hardware connection problem?
The lights on your Network Interface Card indicate when one device is passing data to the other and at what speed. The complete abscence of these lights means that it is in fact a hardware fault. Whether it's your NIC that is damaged or disabled, the pins in the ethernet port distended, bad cable or even the router/switch that you're plugging into malfunctioning will have to be determined.
Things you can do (but would need to physically be there for.)
*Go to device manager on his computer (Right click "My Computer", Properties, Hardware tab, Device Manager.) Expand the Network Adapters portion and double click on his network device. When you look in the device status portion it will ideally say "This device is working properly." which may or may not be true. If it's describing any issues then the problem is likely with your NIC (No drivers installed, corrupt, etc.) and might want to look into procuring another.
*Inspect the inside of the ethernet port on your dad's computer. You're looking at the 8 little metal pins that are arrayed inside. These are traditionally arrayed straight across the width of the port. These pins have to make contact with the pins on the plug of your ethernet cable in order to establish a connection so any distention will obviously cause problems. This is not a very common fault and when it does occur you generally see spotty connectivity (Windows flip flopping back and forth between connected, limited or no connectivity, unplugged) as opposed to a steady "unplugged" but is an easy enough check to warrant a look-see.
*Try a new cable. Make sure that it's NOT a crossover (you can tell by holding both plugs of the cord side by side. The colored wires you see through the clear plastic should be the same for both plugs (probably in this order from left to right and clip on the bottom: WhiteOrange, Orange, WhiteGreen, Blue, WhiteBlue, Green, WhiteBrown, Brown). A crossover will have a several wires in different places. http://en.wikipedia.org/wiki/TIA-568B scroll down to the picture for reference. A crossover has t568A on one side and t568B on the other.
While you're looking that closely, do any wires seem to be pulled back or broken? What about the pins on the plug itself. Any damage or variance might be causing the issue.
*Try a different port on the switch (like the one connected to his laptop) to see if the port has gone bad for whatever reason.