Why can’t I see a computer using FIND

I have 200 computers on a TCP/IP (TCP/IP is the only protocol used on the network)LAN. A printer, that is directly connected to a computer, is used by 3 other computers. I am attempting to setup a 4th computer to print but cannot see the “host” computer. I can ping the IP but cannot see the computer using START/FIND/COMPUTER. The printer network path name does not work either. Please provide suggestions.