They are talking through their posterior, as usual.
If you get a problem that they cannot sort out, they blame you and say this kind of thing.
They should support the livebox regardless of what it may be connected to, xp, media centre, win2000, etc.
try this however: On the laptop
Click Start - Run, type services.msc
This will open a window, scroll down near the bottom and find Windows Zero Configuration - Right Click it and click 'Start' or 'Restart'. you may have to repeat this.
Now check to see if you have a connection with the livebox. This is a Windows problem, rather than a livebox issue, but they could have done this with you.