hacking
 

In a LAN environment, how to hack into another computer? Say, want to get some files.

hack? This site is very strongly against acts such as breaking into other computer systems by dishonest means. There are many networking protcols such as ssh, samba, nfs but if you are genuinly asking how to break into another system then you will not be welcomed back to this site again. If you believe this to be unfair to you or i have misinterpreted your question you may contact me or jeremy privately.