some progress...: The reason why these two computers cant see eachother was:  node-type if you run ipconfig/all, there is an entry         node-type: peer-peer  or something else on win98se it was : broadcast on winxp it was: peer-peer This applys to netbios protocoll being enabled on both computers. On my XP-machine it was set to "peer-peer", on the WIN98se it was "broadcast". peer-peer means, use WINS protocoll to resolve name to IP conversion. Broadcast means, send a broadcast to all computers and the one with the given name shall respond giving me its ip-address. After setting the XP-machine to "broadcast",  ping by name worked. To change it in XP you have to change a registry entry.... HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetBT\Parameters\DhcpNodeType   to 1 (broadcast)   or 8 (hybrid) The current status is: XP can access WIN98SE via network-neighb.  and transfer files. WIn98SE cant see the XP-node at all in netw. neighb.   ???? Furthermore i understand, that WITHOUT NETBIOS, name to IP resolution would require a working DNS server. I was thinking that my DSL-router 4-port HUB would supply this.  (Zycel router). But wrong.  It supplys a DHCP Server but no DNS server for LAN. All it does is forwarding DNS requests to the ISP providers DNS server, that would probably not know about your LAN- computers names. Could it be true, that the ISP DNS-server acts as DNS server for the LAN?