I'm a pretty savvy computer user and this is completely confusing to me. My parents were using a fairly old computer running Windows xp and a BEFCMU10 Cable modem and a WRTG54g Router. The network consists of a computer in our basement which is connected by an ethernet cable and 2 laptops which connect wirelessly.
Then several weeks ago I built a new computer for them running Windows 7 (64 bit) which took the place as the networks central computer, and the old computer was hooked back up. This is where things get odd. After everything was hooked back up the laptops would no longer connect wirelessly, and the old windows xp computer would not connect with a physical ethernet connection.
I had assumed that it was an issue with going from windows XP to Windows 7 and some problem with the old router. So I purchased a new Cisco E1000 router. This solved the wireless problems and the old windows xp computer would connect to the internet. Now that everything was working we decided to move the old computer to a spare bedroom, however once we had everything set back up it wouldn't connect anymore and after testing the integrity of the Ethernet cables we realized that even though they were all intact and functioning the only time the old computer would connect is when it was connected with one specific segment.
Now I've gone through all the network settings and router settings and I cant figure our what to do. If anyone has any suggestions or advice I would be very appreciative.
How did you check the cable? With a simple continuity tester? I have seen cables wired up straight through, without the split pair on pins 3 and 6. These miswired cables test fine with a simple tester, but fail to properly connect.