Device manager shows nothing unusual.
The cable is fine, I even swapped it with one from another computer. Same problem. Besides, the cables all work with the linux install fine.
Latest driver downloaded from the ASUS website for that motherboard.
Broken tcp/ip stack? I dunno the lingo, bit yest, re-installing windows has worked everytime, for a short period. This time it was for 3 days. And this time I did NOT install anything exotic on the system, just adobe reader, dvd burning stuff/power producer and a file utility to zip and get around with, otherwise a clean install.

It is a real puzzle, what would cause XP to see an issue with the network, report it as a disconnected cable and loose connectivity, but Linux sees no problem at all and connects fine?

I bought and installed a network card. It works fine under XP and I have internet again (so far), but this does not solve the riddle, something is still not right.