O&O Defrag Pro

What is included in O&O Defrag Pro?

Automatic Optimization – Detects HDD or SSD and optimizes accordingly.
IntensiveOptimize – Defragments locked files, now supports BitLocker drives.
O&O VisualDisk – Shows SSD and NVMe write access visually.
StartupManager – Manages startup programs and removes faulty entries.
Core Capacity – Five defragmentation methods including STEALTH and SPACE.
Important – Windows Server support and network deployment not included.

What are the main benefits of O&O Defrag Pro?

O&O Defrag Pro is a Windows disk optimizer that reorganizes fragmented files on HDDs and applies write-reducing methods on SSDs and NVMe drives. It runs automatically in the background or on demand to keep a single desktop or notebook responsive over time.

Faster Boot – Boot-time defrag reorganizes locked system files early.
SSD Protection – Reduces unnecessary write cycles, extending drive lifespan.
Hands-Off Maintenance – Automatic background optimization needs no manual scheduling.
Drive Health – S.M.A.R.T. analysis flags failing drives early.
Purchase Model – One-time purchase instead of a subscription model.
ARM Support – Runs natively on ARM-based Windows PCs.

What does O&O Defrag Pro do?

O&O Defrag Pro reorganizes fragmented files on HDDs into contiguous blocks and applies write-reducing optimization on SSDs and NVMe drives. It detects the drive type automatically and offers five defragmentation methods, including STEALTH for fast low-memory runs and SPACE for consolidating free storage. Boot-time optimization handles locked system files before Windows loads, while the IntensiveOptimize mode reboots into an isolated environment to process files that stay locked during normal use. The practical result is quicker program launches and shorter file access times on a single Windows PC.

Who is O&O Defrag Pro best suited for?

O&O Defrag Pro suits anyone running a single Windows 11 or Windows 10 desktop or notebook who wants scheduled maintenance without managing it by hand. On a mixed HDD and SSD system, automatic drive-type detection gives the mechanical disk full defragmentation while the SSD receives only write-minimizing optimization, avoiding needless wear. Experienced users can open the Classic View to control every defragmentation method and scheduling rule, while casual users rely on one-click automatic optimization. It does not centrally manage multiple machines, so administrators covering a network need the Server Edition instead.

How is O&O Defrag Pro different from the Server Edition?

O&O Defrag Pro runs only on Windows 11 and Windows 10 client systems and cannot be installed on a Windows Server operating system. The Server Edition adds support for Windows Server 2016, 2019, 2022 and 2025, plus centralized network management through the O&O Enterprise Management Console and Active Directory integration for controlling defragmentation across many machines. Both editions share the same core engine, the five defragmentation methods, SSD-aware optimization and boot-time defragmentation. Choose Professional for a standalone PC and the Server Edition when you need to deploy and monitor defragmentation across a network.

Does O&O Defrag Pro work on SSDs and NVMe drives?

Yes. O&O Defrag Pro detects SSDs and NVMe drives automatically and switches from classic defragmentation to methods that minimize write operations, since excess writes shorten flash memory lifespan. The O&O VisualDisk feature charts write access to flash storage, so you can see where heavy background writes originate and confirm the optimization is reducing them. Built-in S.M.A.R.T. analysis reports the health of HDDs, SSDs and RAID disks and flags drives that may be nearing failure. Defragmentation is not a replacement for a backup, so critical data should still be copied to separate storage.

Why backups protect against expensive data loss
For more background on backup planning, read our guide:

What should users check before choosing O&O Defrag Pro?

Confirm the target machine runs 64-bit Windows 11 or Windows 10, because O&O Defrag Pro is 64-bit only and does not run on macOS, Linux or Windows Server. Check whether you need to manage several networked computers: the Professional Edition optimizes one PC at a time and has no central deployment, which only the Server Edition provides through the O&O Enterprise Management Console. If your system uses BitLocker, note that the version 31 IntensiveOptimize mode now supports encrypted drives. For SSD-only systems, remember the tool applies gentler write-reducing optimization rather than traditional defragmentation.

Does O&O Defrag Pro run on ARM-based Windows PCs?

Yes. Current versions add native support for ARM processors alongside Intel and AMD, so O&O Defrag Pro runs directly on ARM-based Windows machines without emulation. This lets newer ARM notebooks receive the same automatic optimization and boot-time defragmentation as x86 systems.

How does automatic background defragmentation work in O&O Defrag Pro?

Automatic background optimization is set up in a few clicks and can run when the PC is idle, on chosen weekdays, or while the screensaver is active. It pauses and resumes on its own and remembers where it stopped, so heavy use is not interrupted. You can also exclude periods when demanding applications such as video editing are running.

Can O&O Defrag Pro optimize external and removable drives?

Yes. O&O Defrag Pro supports removable and external drives and can optimize any storage device that Windows recognizes as a standard file-system partition. This lets you maintain USB-connected disks alongside internal HDDs and SSDs from the same interface.