When Apple OS X Leopard (10.5) was launched, one of the biggest marketing points was the inclusion of Time Machine.

Time Machine is the backup program that goes on automatic when using OS X and backs up every file on your Mac automatically to an external hard drive. If you ever want an old version of a particular file, just find the file in Finder and then activate Time Machine. You'll take a very graphical trek into time (pictured to the left) where you can find the old version of the file you want and restore it.

But, did you know that Windows Vista has something somewhat similar to this? Yes it does and it is called Shadow Copy.

Shadow Copy is built into all versions of Windows Vista, although only Vista Business, Enterprise and Ultimate have the necessary GUI setup to work with it from Explorer. But, the idea is that it allows you to browse back in time and restore a file from a past restore point. Shadow Copy is more or less the replacement for System Restore in Windows Vista. If you are running Vista, it runs by default as a Windows service.

Using Shadow Copy, you can restore a single file relatively easily. To do so, right-click on the file you wish to restore. You can also right-click on an entire folder. Then choose "Restore Previous Versions" from the context menu. You'll be presented a list of dates for which you have restore points for the file. Click Open to view it as it was on that day. To restore, just hit Restore.

If you are not running a version of Vista which has this built into the GUI, you can still use the system by downloading a utility called ShadowExplorer. Using that program, you can browse to a particular restore point in the date dropdown, then find the file or folder you wish to restore and select Export.

An Equivalent to Time Machine? No.

On the Mac, Time Machine backs up every hour. In Windows, it creates restore points on a schedule you set. Usually once a day. Any file you wish to restore would need to be tied to a restore point. A restore point is just that - an entire set of files for your computer so you could restore the whole thing. So, given the nature of it, this is certainly NOT Time Machine. Apple's Time Machine is much easier to use and is much more thorough in the backups it does.

Also, Time Machine is set to back up to an external drive. Windows Shadow Copy creates restore points on the system hard drive. This defeats the point usually because hard drive failure is one of the more common reasons to have this type of system in place.

So, Shadow Copy certainly should never be your replacement for a good data backup policy. Mac users, Time Machine can be your backup policy and you need not worry about it aside from that.