How to disable one computer in a netowrk

Disable as in turn them off, or just deny them wireless access? Are these wireless clients you control (iow, other users in your home vs. neighbors who shouldn't be accessing your wireless router)?

You need to expound a little more so we have a better picture of the problem or else we're just left guessing, and that makes it hard to help.

we're both connected to a wireless network and we're using a simple router. i want to disable other computers accessing i-net which is connected on the same network.
is it possible to barred them using of my desktop/laptop?

or do i have to install other software both pc's?

If you want to deny access to your wireless network, you just need to enabled wireless security on your wireless router. Your router's user manual should explain the process.

i can't because they need to connect to our database. so what i want is to disable there computer to access internet.

I have another process used that is by using regedit hlkm process...

Do you control these other computers or are you trying to control the users of these computers?

The simplest/obvious solution is to use firewall rules on the router to exclude computers based on IP and/or MAC address. However, beware that it's trivial to circumvent these restrictions by either manually reconfiguring TCP/IP or MAC spoofing. So it's only going to prevent casual users. Anyone w/ determination and the able to search Google can easily defeat it.

The proper way to solve this problem is to establish a second network in which only the resources to which they have authorization are present. Instead, you’re doing just the opposite; giving them “the keys to kingdom” then hoping to control their behavior through “house rules”. That’s just asking for trouble (imo). Bad boys will be bad boys, trust me.

A better approach is to isolate them on their own network and only add the resources they absolutely need. For example, install a second network adapter (wire or wireless, whichever is more practical) on the database machine and connect it to another wireless router. As long as the existing and new network adapters remain UNBRIDGED, they have no access to your internal network, at all. IOW, they’re limited through ARCHITECTURE.

Anyway, that’s what *I* would do.

i just want to control this computers. my dgm told me to do so.
please tellme
.thnx..

as what i wrote. what i did is i move to there pc and edit the hklm.
but they will notice that im doing some tweaking to disable accessing to net.