Mystery of the Ethernet cable

[raj_head]

I apologise for how long this post will be, i know it must be boring to read it all but i feel i need to get all the info in to help solve the case!

 

First off, im not sure what the differences are between ethernet/cross-over/network cables. I assumed they all did the same job, but perhaps this is the problem, we'll see.

 

Id been using a long 20m cable supplied by my ISP to connect my laptop to the modem in another room. This had worked fine for years, then all of a sudden, the internet started messing up. It kept dropping the connection or saying "limited connectivity" or just running extremely slow. I tried restarting the modem, laptop etc to no avail. I did a thorough check for any viruses but found nothing, tried a different port on the modem and even tried a system restore. Nothing worked. But it worked ok with the Xbox???

 

So i bought a new ethernet cable. The laptop reads this cable fine but the internet just does not load at all. Ive tried it on my Xbox and another laptop and the same result. Perhaps its the wrong cable? But another, newer laptop works fine with it. Ive also tried another 10m cable i had in another room, this works fine on the Xbox but not on the laptop.

 

And finally, i tried another laptop, this worked fine with the new cable once. Now it reads it but does not load the internet.

 

What on earth is going on?