By AOMEI / Last Updated April 26, 2016

Why is Windows 7 backup disk full?

If you set up a scheduled backup on your computer using Windows 7 Backup and Restore, by default, Windows backup will delete the oldest backup version if the backup files takes about 30% of the capacity of the backup disk. If the you keep creating one time backup jobs, the old backups will not get deleted automatically, so you will find out that the backup disk full error after running the backup several times. You are likely will get a message from Action Center telling you that the disk that your backup is saved on doesn’t have enough free space. Then you can click it to manage backup disk space.

Check Backup Disk Space

How to manage backup disk space in Windows 7?

When you click the Check backup disk space notification, it will bring you to the Manage Windows Backup Disk Space window.

View Backups

To free up more disk space, you can click the “Data file backup” option to manually select which backups to delete. When choosing the backup period to delete, you should first consider deleting the oldest backup period to reduce potential data loss.

Delete Backups

If you want to solve this problem the long term way, you can click “System image” to configure how you want Windows to keeps the old backups.

Manage Disk Space

By default, Let Windows manage the space used for backup history is checked, which is the default setting, Windows backups are only allowed to take up no more than 30% of the backup disk capacity. When it reaches 30% range, it will start to delete the oldest backup periods until there is enough space for the next backup to come.

Manage Windows 7 backup disk space in a more flexible way

If your Windows backup failed with not enough disk space error, you should consider using another Windows backup program to better handle backup disk space. In this case, AOMEI Backupper Professional edition is recommended. It allows you to backup system, disks, partitions, files and folders, so almost all kinds of data can be included in the backup.


It provides five different ways to automatically delete old full/incremental/differential backups, so you can choose and specify which backups to keep or delete.

Backup Scheme

As you know, both incremental backup and differential backup only backup changed files. The difference is that incremental backup is based on the last backup while differential backup is based on the last full backup. Therefore, you should not delete any incremental backups until you create a new full backup, but you can delete any previous differential backups as long as you keep the last full backup. You may get confused about which backups to delete when Windows 7 backup disk full. Luckily, with AOMEI Backupper, you will be relieved because AOMEI Backupper will do the calculating and delete the old backups version while the current backups remain valid. Besides backup and restore, you can also use AOMEI Backupper to clone hard drive to SSD or another hard drive.