i would like to ask how to install and configure the DHCP.
Install and configure DHCP on what and for what purpose?
normally, we use dhcp client, not the service portion. Any router provides
the dhcp server function for free. Why would you want to try to administer the
allocation of IP addresses yourself -- not likely to be successful without
Jobeard is correct.
... is an unusual request. Most people who would want to actually 'install and configure' the server portion of DHCP probably know enough about it that they wouldn't have to ask such an open question.
If 'installing and configuring' a DHCP client is your question, then DHCP is intended to be automatic. If your DHCP isn't working, then you probably have another issue we can help you resolve.
i've a 3com router,and i wan to make it as switch,my friend told me to disable the DHCP,so it'll act as switch connect to client.isn't correct to do this way>?
Yes. Read The Friendly Manual
Or, at least tell us the exact model of the router. "A 3com router" is not very helpful.
ok,the model of the router was 3com officeConnect cable/DSL Gateway.
officeConnect is an entire series of products and does not help much either.
Really, didn't you get a manual with your router? Take a look - reading English can't be that bad, can it?
Type the IP of your router in your IE (in the URL box), and you will connect to your router. Type the password (sometimes there is no pass), and you will come to router setup.