Network sharing error

Hi friends anybody help me, win 7 os installed my system connected with lan my system not connect other system when other system to access my system sharing folder could n’t connect that folder, ( firewall are disable file sharing is enabled )
below this warning error is created

( \\192.168.1.20 ) IP not accesible, you might n’t have persmission to use this network resource. contact the administrator of this server to find out if u have access permisson

the trust relationship between this workstation and the primary domain failed