regarding filesharing

i have connected 3 computers on a network. i am sharing
the internet in 3 computers but i couldn't share the
files and printer.i checked the boxes "SHARE THIS FOLDER
ON THE NETWORK", but i couldn't see this file on other
computer.
when i am clicking the "MY NETWORK PLACES" it's
showing only my computer shared files.
but when i am clicking the "VIEW WORKGROUP COMPUTERS"
i can see the other computer on my network.when i am
trying to open that other computer"BANDARI(other
computer's name) is not accessible.you might not have
permission to use this network resourse.Contact the
administrator of this server to find out if u have access
permissions.

the networkpath was not found."
can u please tell me how to solve this problem