Are you using a crossover cable, or a straight through? Some systems can't use a straight cable hooked to another PC.

I already used the cable, that I'm using now, in the past to connect with another laptop and it worked(i could transfer files from one to another pc). I even switched the UTP cable that i used for the internet with the one i used for connection between pc's(that cable also worked when I helped a friend to connect his laptop to his pc).
This al was just a month ago; what are the chances both cables malfunctioning in such a short period?? I'd say none, don't you think so too?

I think I'm using a crossover cable, but I'm not sure. On both connectors, I can see "X' over".I think that means crossover, right? thanks

Hello,

For $30 to $40, you can get a small ethernet hub / switch, and remove all confusion involving crossover cables vs. normal ones. Save yourself the grief, and get the proper hardware.

Christian

"X over" indicates a crossover cable, yes.

Do you get the "cable unplugged" error when you plug the laptop directly into the cable modem, or when the laptop is plugged into any other network device aside from your desktop machine?

A hub or switch won't usually do the trick on a Cable or DSL Internet connection, as the ISPs only allow/provide 1 IP address with normal Internet access accounts. You can physically connect more than one computer to the hub/switch, but only the first computer to log on to the Internet will be authorized, receive an IP, and be able to surf; the second computer will be denied access.

A broadband router provides the functionality needed, but they do cost more than a hub or simple switch (a good router runs around $60 USD).

Yes, I know all that. My ISP is from my university and according to a friend a hub won't do the trick; a router would. But the problem is that I'm a very poor engineering student, and I can't afford an expensive router(in Belgium the min. price is about 70 euro for a router!!!!!!!). But i do have the 3 ethernetcards; so you see my dilemma.

And I only get the unplugged error when there is a connection between laptop and pc. I can surf on the internet with both computers(over de cable modem connection).

Let me ask a possibly stupid question:
Regardless of the fact that you're getting the message about the unplugged cable, do the two computers appear to be communicating at all? Can you ping each machine from the other? If the laptop is set for DHCP and the desktop is configured to provide an IP to the laptop, does it?

no connectivity at all!! when i try the ipconfig command in cmd window i get "media disconected", as I expected.

Look under the Advanced tab in the hardware properties of each computer's NIC and make sure that the Link, Duplex, etc. settings are in agreement with the way the NICs should be communicating/negotiating. If the NICs are currently set to auto detect their speed and duplex modes, hard-set those options to the correct settings (100Mbps/Full Duplex, 1Gbps/Half Duplex, etc.)