I connect to internet with dhcpcd, but only root can execute that command even though i have used chmod. Also i want to launch it at startup, what do i do?

You have probably not received replies yet because this question is not clearly phrased (I'm trying to be helpful).

If you were to reply with information like the following, you may receive more replies:
*) the GNU/Linux distribution that you use (e.g. Redhat 7.3)
*) what you are trying to do (e.g. get my computer to the point that I can just log in to GNOME/KDE and use the internet

Most likely, you need to configure the network interface (NIC) using the tools of the distribution that you use. Read the manuals that come with your distribution, most likely it will be clearly explained there also. The chmod approach is incorrect.

I have Slackware 9.
I want to connect to internet with adsl. If i launch dhcpcd as root it works fine but i want linux to start dhcpcd automaticly, or maybe there's another way to do the same thing.
Help is appreciated.

Sounds to me like you need to either run netconf again and choose DHCP or take a look at /etc/rc.d/rc.inet1 and /etc/rc.inet2 for the relevant places to runDHCP at startup.

HTH

Jamie...

Thank you, it worked after i had run netconfig.