My DSL line is working. I think so, at least. After testing several computers, modems, USB and phone cables, calling France-Télécom to check the line... They told me my line had been "ungrouped" (how do you say that? This is the further step in accessing DSL) - and my "old" modem wasn't compatible any more. As Free (my provider) sent me graciously a Freebox - their own modem, I didn't ask for anything, but I'm a faithful customer :-) - I installed it again. I already did that, but the line was unstable. My dear neighbour Jean-Pierre advised me to open a MSN account to keep the line open.
And I should be able to have free phone access, and even some TV channels. Waoh.
Crossing fingers! I hope I'll be able to get my usual Internet fix again. Phew.
I should have asked Foxy, he knows better.