What backup settings should I use to maximize my disk space?

Windows Backup provides you with the flexibility of managing the disk space that is used by your backups. After you set up Windows Backup, you can view how much disk space is being used by the backup and how much free space you have on the disk that your backups are being saved on by going to the Backup and Restore Control Panel. To control how much disk space is being used, you can choose how many file backups and how many system images Windows keeps. The following information can help you when deciding how best to manage your backup disk space:

  • Backups are created in sets known as backup periods. To help maximize your disk space, Windows Backup backs up all selected folders the first time it's run and then it only backs up files that are new or have been modified since the last backup was made. Periodically, Windows creates a new, full backup. Each full backup is known as a backup period. When you view your file backups, you see all of the backup periods labeled with date ranges. If you decide to delete file backups, you should always keep the most recent file backup.

  • By default, Windows automatically saves as many system images as it has space for without taking up more than 30 percent of space on the backup disk. Once the disk starts running out of room, Windows deletes older system images. You can set Windows to retain as many system images as it has space for on the backup disk or to only keep the most recent system image. You should always keep the most recent system image. If you are saving your system image on a network location, you can only keep the most recent system image.

To view and manage your backup disk space

  1. Open Backup and Restore by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Backup and Restore.

  2. Click Manage space. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.


    • If you haven't set up backup, you won't see Manage space.

  3. To change the amount of space that is used by file backups, under Data file backup, click View backups.

    You can then select and delete older file backups.

  4. To change the amount of space that is used by system image backups, under System image, click Change settings.

    You can then choose to have Windows save older system image backups or just the most recent system image backup.

To manage disk space for a file backup that was created on another computer

If you have a drive that contains file backups that were made using a different computer, you can use your current computer to delete older backups on that drive by following these steps:

  1. Open the location where the backup is saved.

    For example, if you backed up your files to an external hard drive labeled "E," connect the external hard drive to your computer, and then open drive E.

    Backups are saved in this format: backup location\computer name\Backup Set year-month-day time. For example, if your computer name is Computer, your backup location is E, and you backed up on April 2, 2008 at 16:32:00, that backup would be located in E:\Computer\Backup Set 2008-02-04 163200.

    The date and time shown in the example is in Pacific Standard time. You might need to adjust this to your time zone.

  2. Right-click the computer name of the backup that you want to delete, and then click Open.

  3. Right-click the folder containing the backup you want to delete, and then click Delete.