how can i configure a fileserver in redhat linux but the clients computers run on windows xp and managing the intranet in our company.

Please tell me

For intranet you would use a http server, like Apache (apache2 actually).

For file serving..well it depends on what kind of fileserver it needs to be. If you like to "share directories", then I guess you need Samba (it uses the SMB protocol which Windows uses in network shares too). Or you could run a ftp server using ftpd. Or you could do a thousand things, but I guess Samba is what you're looking for..(or if it's not, post back).

EDIT: and I'm not posting any "how-to"s for this matter since there already are such articles..search Google and these LQ forums for how you set up Samba sharing and Apache/web-server.

i think samba is what i am looking for but i dont know how to configure it in a manner that anyone can't get access to the directories even if there are shared.
About intranet, i have a router and a computer which i want to be a network server then i want to know if it is possible to connect a wire which give us internet to the server and from the server i connect the router which will distribute the internet and intranet to the clients computer because i fear of virus and spywares that is why i want to pass the internet connection in the server and i distribute it.

thanks

You should be able to configure Samba so not everyone can use the shares; with Samba you can do, as far as I know, everything you could do with Windows when sharing directories.

Then the internet thing. You can achieve this in many ways, again, but you should remember one thing: even if you did use the server as a proxy or just forward all the internet connections through it, and the server contained Linux (and thus shouldn't get infected by viruses too easily), all the internet connections that can pass through - the ordinary ones - can still carry bad things along to your workstations (viruses, trojans etc.) You can probably filter some of the content (like emails), but it's not perfect; you still need personal firewalls and antivirus software etc. on your workstations. Anyway, you can make your server a web server (for the intranet) using Apache or some server software of your choice; then you can, using iptables for example, set the server "share it's internet connection" with the clients, thus achiving what you described.

Read more from samba.org (file sharing), apache.org (web server) and iptables.org (Linux's "built-in" answer to firewalling, routing, forwarding, NATing, masquerading and more).