i want to boot my system by lan. and then how can i use installation files placed on another system

Hello and welcome to LinuxQuestions,

Way to little information to give you a straightforward answer. What distro are you planning to use, does your NIC support PXE booting? LinuxQuestions users are at their best when trying to solve problems you might encounter with Linux. But for step by step guides or howtos this isn't the place to come to. Meanwhile, have a look at Google to find some instructions. I used the search string PXE boot linux and the first links that came up are these:
http://linux-sxs.org/internet_serving/pxeboot.html
The complete result: By Google

Kind regards,

Eric

You can install from another system which should be configured as NFS server or FTP server or Apache server. You will need a bootable cd to start the installation process.

Sounds like you want to do pxe boot type installation. Unless you tell us the specifics of your boot server OS and intended install OS, we can't really give you much more information.

Evo2.