This is an endlessly recurring theme I find on forums: you got a Mac, your roommate/significant other has a Mac or a Windows PC, now you want to share your internet connection, a printer, files, etc., but you're stuck trying to connect computers together peer-to-peer. So you come to a forum... A bunch of people respond: "hmm, it works fine for me", or "I have the same problem", or "why don't you try this..." (and its something completely different). I am going to address some of the "why don't you try this..." responses, because it may seem to you like the person is blowing off your question or admitting some functionality is not working; however, this may not be the case. For instance: "how do I share my internet connection from machine A with machine B". <-- You just announced to the world that you do not have a router with a firewall (which start at ~$40) and probably have some (Winders) boxes connected directly to the internet. Once your above question is answered and the problem is resolved, your machines are likely exposed and now machine A always has to be turned on in order for machine B to have internet access. This does not sound like the Mac experience you likely sought when purchasing a Mac. Actually the above example does not require a Mac. Rather, this is a very basic home network configuration I highly recommend: Your Internet Service Provider | (DSL or Cable or etc.) modem. Might be all-in-one with... | Router (with firewall turned on!) <- a lovely piece of equipment you're trying to work around. Why? | Mac || PC || network printer* || file, web, ftp, etc. server || etc. peers connected to router * another thing of greatness people work around peer-to-peer Not only would the peer-to-peer communication issues become obsolete: clients are protected by an internet firewall a particular computer does not need to be turned on in order for a particular service to work it is scalable if something breaks, like the router (which is rare), now you have an option B to try to connect peers together until the network is up again saves time cost effective etc. Because it is so cost effective to obtain these benefits, a lot of the most knowledgeable people about networking might have never tried what you're trying. Being a cheapskate on network components, I have a ~$100 router (there are cheaper ones), an even cheaper printer server (no built in ethernet on my printer), & retired desktop PC became my Linux web/ftp/file/etc. server. An OS X or Linux server could handle all your needs with free, open source software following open standards. OS X and Linux servers deploy more secure protocols like SSH(fs) and this way you don't have to try to communicate directly with Windows machines. MS tries to make that harder hoping you won't choose non-MS software. Now I have no Windows machines so obsoleted the need for Samba on the Linux file server (to emulate Windows File Sharing), but as I recall that was the least secure, yet most complex protocol to set-up on my network.