cable works for other computers doesn't necessarily mean it will for those two. Most newer hardware is 1 Gbps, but older hardware likely is not. If you plug both computers into "downlink" (as opposed to the single "uplink", which won't help you) ports on a router and use straight (and not crossover) Ethernet cables, you at least alleviate this problem. It will also enable you to test the network connectivity of each to the router - and in so doing, the ability of the network to support the connection from one to the other. So: straight Ethernet cables from each to the router. Then, open a command line on each computer and type in "ipconfig /all" and then hit the Enter key. It will look something like this: C:\users\ your username &gt; ipconfig /all [b]Windows IP Configuration Host Name . . . . . . etc. [b] Look for the lines that read "IPv4 Address" and "Default Gateway". The first is the IP address of that computer. The second is the IP address of your router. If you don't see those lines, then your network connections are not working. Try a full shutdown and start-up in case your network adapter cached a bad IP address. Typically, the IP address will look something like 192.168.1.???, where ??? is a number between 2 and 254. Sometimes, the third number 1 will be different. Bu if you see 169.254.???.???, then your network adapter on your computer is not successfully connecting to your router