On my home network I have 1 Desktop PC with Windows 10, a Laptop with Windows 10 as well as an Apple iMac with OS X 10.6.8

I am sharing files with all 3 machines and on the laptop I can see all 3 of them but not from the Desktop. I can also see all the PC's from teiMac. I also share printers on both the iMAc and the Desktop. On the Desktop PC I cannot see the iMac but can print to a printer which is hardwired to the Mac. What do I need to do in order to see the Mac on the home network tree from the Desktop?

Any help wpold be gratefully appreciated,