It's quite impressive how many different sorts of backup we've put into Vista, and the launch of home server adds another one. You can:

1. Image your machine using imageX: this is really geared to installing or reinstalling, but you can use a WIM file as a giant, single instanced ZIP file. WIM files are maintainable, and easy to rebuild a system from.
2. On the business and Ultimate editions, use CompletePC backup (from the Back-up and Restore centre) to create a VHD file backup which is an image of the disk; you boot into the Recovery Environment and and re-instate a system from the VHD - though it's not very maintainable.
3. Use Vista Restore points. Windows XP creates system restore points, but these are concerned with rolling back changes to the OS. A Vista restore point is a shadow copy of everything (pretty much – there are some exclusions). This is the engine behind part of the "Previous versions" tab on the file properties dialog box.
4. Vista backup (with Scheduling) – a backup of everything except Program files and Windows folders. It's intended for "configure and forget" use, so that files get written to a second hard disk or a file server as a scheduled task. The catalog of backed-up files also appears in the previous versions tab.
5. Folder re-direction - which isn't new to Vista. On server 2003 you can enable shadow copies and these will be visible on Windows 2000 or XP with a suitable update applied: in Vista these copies are also shown through the Previous versions tab without the need to add anything. .

Now there is some confusion about system protection. First if you turn on system protection (from the option on the left of the Computer/Properties or Control Panel/System dialogs) then a scheduled process will create a restore point at Midnight (or when the system is next awake) and every time it boots. Older restore points are moved off the system to make way for new ones. That's the version you can restore to: you can't restore to a version between restore points. Vista doesn't keep every version you save, but it does give you a daily backup.

Secondly Backups are listed on the previous versions tab whether the file has changed or not. However shadow copies only appear after the file has changed.

Most of us are used to "off computer" backups, but not a "revert" facility that we can carry with us. Shadow copies aren't supposed to keep versions forever – the system will push out old backups to make way for new ones - and that kind of thing is best done with a true backup. However the is a security implication because if you lost your laptop a confidential document which you recently deleted may still be recoverable via shadow copy ... all the more reason to use technologies like bit locker.

With Home server we have an additional client which backs up any machines you have at home to the server. Flexibility is great, but I do wonder if we're creating confusion with all these options.

Now here's a thing. I was looking for somewhere to send you for more information. IT's Showtime has a video called "New Backup and offline files features in Windows Vista" It contains this "hockey stick" graph showing how we expect the amount of data in homes, and the average size of disk in use. And from that we estimate the demand for home file servers. Which brings us back to Windows home server....

Postscript. One of the teachers at my school was famous for throwing erasers out of the window of his classroom. He used to say if you can rub-out your mistakes you're more likely to make them. So this morning I managed to shift-delete a folder instead of a file... and shadow copy brought it back. I wonder if the mere act of thinking about Shadow copy made me careless :-)