alsalam 3laikm

dear brother i connect the computers by puting network card (pci) and a swich. i connect 1 computer to the internet by dsl modem and the others inter to the internet throw this computer and i made sharing for the harddisks and i can see all the computers which in my network group.now i have RH 9 i connect to my network so now i can inter to the internet but i can't see this computer in my network or see the other computers in this computer even i give this pc a name .

Salamo 3alaikom,

It seems you are still very new to the Linux world. Well your words translate to me that you need in the linux machine to have smb-client to be running in order for the linux machine to see the hard disks on the Windows machines.
For your RH 9 machine to use the router as the gateway, If you use a router as u say then this most probably means that the router is the Gateway for all the machines on the network. Use its IP as the Gateway for your Internet connection that way you can go online via the router. I have an advise to you is to attach the router to the Linux machine and use the linux machine as a firewall for the whole network since this is the most secure thing for your network.
In order to let the Windows machines to see your HDs, you have to do 2 things. First, to have the smb-server working and running (I hope you installed it as well), second to make shares in your filesystem so as to be used by the smb-server.

For more information about what i am saying you should read the RHL documentation.

Salam.