Configuring the Routers and Computers
By default, the Windows Live Sync software tries to configure your router for you using UPnP. If your router supports it, you may not have to do any manual configuring. However, if the computers don't show up as being “Online” on your Windows Live Sync account page, it’s probably because your router doesn't support UPnP and the software can't work automatically, or the firewall on your PC is blocking the communication. Their Help files can point you in the right direction.
Setting Up a Folder to Sync
Once your computers are “Online,” you can start syncing. However, on the computers from which you want to host folders, you must first enable remote access. You don't have to enable this on computers that aren't hosting folders, even if you want them to stay synchronized with other PCs. To enable remote access on the host computers, click the Windows Live Sync icon in the system tray, hover over More, and click Settings. Then check the Allow Remote Access to This Computer option, as Figure 2 shows.
Figure 2 Allowing remote access.
Now you can use the Windows Live Sync site to set up personal foldersthose folders you want to share only among your PCs, not with others. Simply click the Create a Personal Folder link. Next, select the computer that has the folder you want to share. Then browse for the desired folder. Once you are inside the folder, click the Sync Folder Here icon/link, such as Figure 3 shows. Now select a computer you want the folder synchronized toyou can add more computers later. On the next screen, choose a folder to use for the synchronization. If the folder already contains files, they will also be synchronized. Finally, choose whether you want automatic or on-demand synchronization; automatic is probably the best choice.
Figure 3 System Folder Here icon.
If you have more than two computers that you want to be synchronized, you can add easily additional computers to your personal folders. Simply click the folder's icon on the Windows Live Sync site and on the folder page, click the Add a Computer link (see Figure 4).
Figure 4 Synchronizing more computers.