I am going to throw out where I think you need to look to fix your problem. Also, make sure you have the same protocols loaded on all the machines. Give those a try and if you can't find the answer you need, post your results and we will see if we can help. I've been told this is acceptable. I've been told this is acceptable.
All computers can share printers and files.
It can't detect each other. Any help will be highly appreciated. Please take note that I am just an amateur computer user. Net is the opinions of its users. Such opinions may not be accurate and they are to be used at your own risk.