addin a spare pc

You can install Boinc on your spare pc first,and when the benchmarks has run
copy all boinc file to a pc which can access Internet to add project.When program has downloaded necessary flies,quit,copy all back to your spare pc.

Hi Ceri,

What you would normally do in this case is get an integrated switch/router/firewall (always a good idea to have a firewall function on "always on" broadband connections). Netgear makes a decent switch/router/firewall for about $50 US. As Mike said, you will also need an Ethernet adapter for the spare PC if it doesn't already have one (D-Link makes a good PCI one that works with Mac, Linux, and Windows OSs for about $10 US), and a couple straight-through Ethernet cables (if you buy a switch/router it will probably come with one such cable). Here's how you hook everything up: (1)connect the router port on the integrated switch/router/firewall to your broadband modem and (2)hook the Ethernet ports on your computers to a couple switchports on the switch/router/firewall. You will probably want to run through the DHCP setup on your switch/router/firewall (the Netgear box will operate as a DHCP server as well), and enable that function (otherwise, you will have to manually configure the TCP/IP settings on your computers). You should be good to go!

Edit: Another, less expensive option (if the operating system in one of your PCs supports Internet connection sharing) is to just get two Ethernet adapters (one for the spare system if it doesn't already have one, and the second for whichever PC has an OS that supports Internet connection sharing -- yes one PC will have two network adapters). To make this setup work, all you do is hook up the network adapter on one PC to the second network adapter in the other PC -- NOTE: if you're hooking up two Ethernet adapters directly, you use an Ethernet CROSSOVER cable, and NOT an Ethernet straight-through cable (the PC that supports Internet connection sharing will also have a connection to your broadband modem). Then, all you do is enable and configure Internet connection sharing in your OS. The downside to this method is that the throughput won't be as fast as with a hardware switch/router, but if the second machine is only running Einstein, it will probably be fine. Here's a good article if you're trying to setup Internet connection sharing for Windows XP: http://www.microsoft.com/windowsxp/using/networking/expert/crawford_02july01.mspx