Microsoft has released Windows Live Sync, a free utility that syncs folders among two or more computers and makes it possible to share synced folders with others. It is the successor to Foldershare – and really not much more than a facelift for Foldershare. It accomplishes an important goal for Microsoft, though, by integrating the service with the Windows Live ID authentication that is driving all the other online services from Microsoft. Here’s the blog from the Windows Live Sync team.

WindowsLiveSync

If you’re not familiar with Foldershare, here’s some background and an explanation of the basic principles. Windows Live Sync runs continuously on your computer; you can designate any folder and Windows Live Sync will copy the contents of that folder to any other computer of your choice running the software. The two folders will then always be kept in sync – if something is deleted from the folder at one end, the same file will be deleted at the other end, for example.

The program only copies files when both computers are turned on and running the program online at the same time. That can cause confusion – I know people who shut down their office computer at the end of the day, went home and turned on their home computer, and were disappointed that they didn’t have their synced files. I was ready to criticize them for being unclear on the concept but what I found was that this is a hard concept and frequently leaves people confused or frustrated. I don’t want to dissuade you from trying it! Just plan to give it some attention until you have that “Aha!” moment.

Windows Live Sync closely overlaps the Live Mesh service, but as far as I know the two services run on completely different underpinnings. I have this vision of the two Microsoft teams fighting it out for dominance and we’ll find out at some random time which one is the victor and which program will die. Maybe they’ll both live forever. Maybe they’ll both be renamed and squished together by spring. Who knows?

There’s an interesting detail in one blog today: apparently Windows Live Sync will be quietly included with every copy of a new version of Windows Live Photo Gallery due soon. That might just be to help people make their photos available on every computer in the house, or perhaps to make it easy to share photos with friends and grandparents. But I’ve also seen speculation that it will be set up to automatically copy your photos to the online photo storage space provided for free by Microsoft (which is now tied in to the Skydrive service). This will take careful work – many people are overwhelmed by all the names floating around and are ready to drop out at the first confusing bit.

FOLDERSHARE USERS: You’ll be prompted to install this update automatically. There may be some confusing bits – you’ll have to associate it with a Windows Live ID (and create one if you haven’t done that yet), and you’ll have to start from scratch to set up shared folders with others. Let me know if you have any problems!