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Modern UI guide

O&O Defrag analyzes and optimizes the way Windows stores files on hard disks and SSDs. It helps you decide whether a drive needs attention, run an appropriate optimization, and maintain drives automatically.

This English guide covers O&O Defrag 32 and the current Modern UI, recognizable by pages such as Overview, Drive Optimization, and Schedules. Features depend on your installed build, edition, and license. Instructions use the English names of controls. For the ribbon interface, use the separate Classic UI guide.

Start here​

See Modern UI and Classic UI for an overview of the two interfaces and why Modern UI is the recommended starting point.

What optimization does​

Defragmentation joins parts of files that are stored in separate locations. Some methods also consolidate free space or arrange files according to a sorting policy. On an HDD, this can reduce mechanical seeking. On an SSD, the aim is to reduce unnecessary file-system work while limiting writes. SSD TRIM is a separate maintenance operation.

O&O Defrag preserves file contents during normal optimization. It does not replace a backup, repair physically damaged hardware, or recover deleted files. The optional cleanup and repair tools have their own actions and confirmations.

How to use this guide​

Follow numbered steps for a task. Tables compare settings and methods. Notes explain differences that affect the result. You can use the sidebar for chapter navigation, the page contents list for headings, and the previous/next links to read the guide in order.

Before reorganizing important data, keep a current backup. Save your work before any procedure that restarts Windows. If a drive reports hardware problems or read errors, start with drive health and troubleshooting.