Why do restore points in Windows Vista use so much disk space?

Why do restore points in Windows Vista use so much disk space?

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A reader asked us why restore points are so large in Windows Vista compared to Windows XP. He notes “The average XP restore point was around 50 MB.  On Vista, restores points vary between 1 GB - 3 GB.” Why the big difference? Eduardo Laureano, the Program Manager for System Restore, explains:

In Windows Vista, System Restore is now based on the VSS technology, which keeps track of block-level changes across your entire volume(s). In contrast, Windows XP System Restore would keep copies of changed system files by using a file system filter. The Windows XP method isn't performance efficient because it works above the file system level, impacting every system operation. It is also not consistent as it doesn't have needed information across the entire volume. It wouldn't restore, for instance, applications that place binaries (purposely or maliciously) in the user profile.

These new restore points, aka Shadow Copies, are taken daily across your volume, or at application/driver installation. The size of each shadow copy will vary on the amount of changed blocks are being recorded on your system. The more it churns, more data will be stored aside. Once they reach their cap, 15% of your volume, older shadow copies will be deleted to free up room for new ones. With these improvements in place, the Windows Vista solution allows for a more reliable (restore points are readily available), robust (supports a much broader set of repair scenarios) and efficient (seamless impact on performance) System Restore.

The tradeoff of taking additional space is compensated by allowing features like Shadow Copy to work as an automatic local backup. With that you can restore previous versions of accidentally edited/deleted files and folders across your entire disk.


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  • You may have noticed that Restore Points on Vista take a lot more than the usual 50 or so megs as they did on XP. They can take up as much as 3GB at times. If you ever wondered why,...

  • The System Restore would make sense to me if you can save a restore point.

    We spend hours reformatting and doing a clean install then many more hours putting everything back. I want to be able to do a clean install, do all upgrades make a restore point, save that point and then 3-6 months down the road if need be, restore to the saved point. Only that makes sense to me. Im looking at my restore points on this new pc after doing all the upgrades and the first restore points are already long gone and those are the ones I need.

  • theminhb, you can use Complete PC Backup (included in Ultimate/Business editions of Vista) to save an image of your computer to DVD. This gives you a permanent, point-in-time image of your operating system.