Can I connect two computers together side by side and use the same internet and mail without a router?You could set up an Ethernet wired cable connection between the 2 computers and establish a network thereby giving you access to each computer from the other. However you would only be able to access the online facilities for whatever via the one that was either wired to your router or had the router dongle for wireless reception on it (or a built in wi=fi card). Given the low cost of wireless dongle receiver/transmitters why would you not give each computer it's ability to connect to your ISP modem/router? truenorthI'd add a router between your modem and computer vs CONNECTED directly between DSL or Broadband Modem and Computer for added HARDWARE firewall security personally, i have little trust in microsofts software firewall, or any other local software firewall directly exposed out to the web. If I read this right you want to have 2 computers connected to the internet both connected through your internet connection without use of a router.

I also agree with truenorth's statement of why not have each computer connected out to the web with their own connection. Such as USB wireless Network adapters are cheap. You then just need a router with wifi and connect them to the router and be all set.

If one was determined to make both computers connect out to the internet through a shared connection on 1 computer, the computer that is sharing the internet connection with the modem would need to have 2 network adapters. You then need to set internet connection sharing on the 1 computer that acts as the gateway for the other computer. You then have to have a peer to peer network between these 2 computers using a cross over cable since if we have no network switch as well a cross over cable is needed to tie the TX and RX between the two computers. The computer acting as a gateway has to be connected to the internet and running in order for computer #2 to connect through it out to the web.

Personally I have only DONE this twice in my life for a shared 56k dial-up connection long ago on 2 computers running Windows XP Pro in which 2 people needed internet access at the same time, high speed internet was not available at their location, and they did not want to pay 2x the cost for their internet requiring 2 dial-up accounts with their PROVIDER as well as did not want to have to add an additional phone line for a 2nd dial-up connection. So I set them up with 2 Windows XP Pro computers sharing a single dial-up connection as was the CHEAPEST solution for my customer, as well as set this up to work in my home for shared dial-up connection between my wife and I with computers back to back like 11 years ago. As long as no one was performing downloads and was only surfing and accessing e-mail or chatting online etc everything worked well. BUT if one or both people decided to download at same time through shared dial-up, you are looking at a coffee break x 2 in how long it would take to complete.

With broadband, I have only used a setup with a gateway where all internet went through 1 computer back when I was using a free SQUID Proxy to speed up frequently visited sites back when I first got broadband and only had a 1mbps upload and 4mbps download service plan with my ISP and was also using VoIP which was competing for bandwidth. But when that changed to 6mbps upload and 20mbps download there was no need to make it any faster, so I shut my SQUID Proxy off. SQUID can be used to make a computer act as a gateway for more than 1 other computer connecting through the shared internet connection. I believe that the Internet Connection Sharing back in the days of XP was limited to 1 other computer sharing the internet connection of the gateway system that was connected and sharing it.