In Windows 7's built-in backup feature, the system typically retains only the most recent system image on the backup disk unless manual settings are adjusted. The "30% backup disk space used" isn't a fixed threshold for storing multiple system images. Instead, Windows manages the space dynamically. Here's how Windows 7 handle system image backups and disk space usage: 1. Single System Image: By default, Windows Backup allows only one complete system image to be stored on the backup disk at a time. When a new backup is created, it replaces the previous one to ensure that the most recent system image is available. 2. Incremental Backups: While the system image remains one full backup, Windows does use additional space on the...