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Frequently Asked Questions

General​

Is there a Free Edition of O&O DiskImage 23?​

No. This guide covers O&O DiskImage 23 Premium Edition. It does not describe a separate Free Edition.

Which backup should I create first?​

For most users, the first backup should be Back up your PC. It protects the operating system, installed applications, settings, and personal data. After that, you can add more focused drive or file backups if you need them.

What is the difference between a backup set and a backup run?​

A backup set is the stored configuration and history for a backup task. A backup run is one execution of that set. For example, a weekly PC backup is one backup set; each weekly result is a backup run in that set.

Where should I store backups?​

Use storage that is separate from the source data. A USB drive, NAS share, WebDAV destination, or S3-compatible storage is safer than another folder on the same internal disk. If the system disk fails, a backup stored on that same disk may be lost with it.

Backup Options​

Should I use full, incremental, or differential backups?​

Use incremental for regular protection because it creates one full backup first and then stores only changes. Use differential when you want each change backup to depend only on the last full backup. Use full when each backup must stand on its own and storage space is less important.

Used-sectors imaging backs up only the sectors that contain data. It is usually much smaller and faster than a forensic image. Use forensic options only when you need a bit-precise copy of the entire source, including empty sectors.

Can encrypted backups be restored without the password?​

No. If you set a password, keep it in a safe place. Without that password, the backup cannot be restored.

Why are VHD and VHDX options limited?​

VHD and VHDX are virtual disk formats. They are useful when you want Windows or virtualization tools to mount a backup as a virtual disk, but they do not support all O&O DiskImage options. The O&O DiskImage format is the recommended format for normal backup and restore workflows.

Scheduling​

Can O&O DiskImage run backups automatically?​

Yes. A backup set can run once, daily, weekly, hourly, continuously, or when the configured backup drive is connected.

What does continuous backup mean?​

Continuous backup starts another backup after the previous one completes and the configured interval has passed. It can be useful for very active critical data, but it can also consume storage, CPU, disk I/O, and network bandwidth quickly.

What is hotplug backup?​

Hotplug backup starts when the configured USB or removable backup drive becomes available. O&O DiskImage stores more than just the drive letter when possible, including drive identity information such as serial number, label, size, and model, so the wrong drive is less likely to trigger the backup.

Restore And Recovery​

Can I restore only one file?​

Yes. For file backups, you can restore the entire backup or select individual directories and files. For image backups, you can mount supported backup files as read-only drives and copy out files with Windows Explorer.

Can I restore to a smaller partition?​

A restore target must have enough room for the used data plus required filesystem overhead. O&O DiskImage checks target size before restore and warns when the target is too small.

What is Fortress Mode?​

Fortress Mode installs O&O DiskImage into the local Windows Recovery Environment. It lets you start recovery on the same PC even if normal Windows no longer starts, without requiring a separate USB recovery drive.

Troubleshooting​

A scheduled backup did not run. What should I check?​

Confirm that the PC was available, the destination was reachable, credentials were stored for network destinations, and the backup set still exists. Then open Reports to check the last result and enable logging if support needs more detail.

My NAS backup asks for credentials.​

Enter the username and password for the network share in the backup options or destination settings. Credentials are stored through Windows Credential Manager so scheduled and manual backups can access the share after reboot.

The backup drive is full.​

Review retention policy, reduce backup frequency, switch from full to incremental backups where appropriate, or use a larger destination. Do not delete random files from an incremental chain unless you are sure no later backups depend on them.