thank you for your help.
The content of etc/sysconfig/network is simple :
The content of /etc/sysconfig/network-scripts/ifcfg-eth0 is
the result of the command sbin/chkconfig --list network is
network 0:Arrêt 1:Arrêt 2:Marche 3:Marche 4:Marche 5:Marche 6:Arrêt
besides in the mandrake network & internet configuration form the checkbox start on boot is positioned to yes. I believe that it comes from the reading of the ifcfg-eth0 file.
Nevertheless I still have to reconfigure my internet connection on mandrakeconnect each time I boot.
It also says that the driver of the device is ne2k-pci when I configure the card with drakeconnect.
When I look to the new card specifications I have the followings :
Vendeur: D-Link Inc
Identification de Bus: 1186:1300:1186:1303
Position sur le bus: 0:9:0
Description: DFE 538 TX
Classe de matériel: NETWORK_ETHERNEt
I read something about modules, it seems that that is what launches the drivers at boot.
My feeling is that something goes wrong when the system tries to launch the module of eth0 at boot because.....I do not know
And I do not know how to analyze farther !