You're probably steamrolling right over the issue. That is to say, not fixing a single issue, instead, you're just trying everything hoping that it fixes something (I do it all the time...sigh)
Have you tried to use a basic switch and connected the desktop and laptop to it, then assign them both an IP address in the same network? I.e. 192.168.0.1 and 192.168.0.2 with a subnet of 255.255.255.0? If you do that, you should be able to share files between the two without an issue. If you can't, then there's an issue going on with the NIC or the cabling/switch.
External Ethernet Adapters are squirrelly at best. I try not to use them at all. If your onboard port is dead, buying a new add-in card will often bypass the issue.
I'm a bit confused by your response however. You said:
Originally Posted by namezox
The thing is that I am unable to connect to my dsl modem on my laptop with the same WIRE and i can surf the web fine.
So, which part is right? The DSL modem does or doesn't work on the laptop?