O&O Defrag 21 has an English user interface that is clearly designed. The tool is suitable for both professionals and beginners thanks to the easy operation. Various menu items can be found in the upper area of the window and the program displays extensive details about the selected functions in the middle of the window. The Tune-Up software supports all popular hard drive types and file systems. The users can choose between the O&O Defrag function, the O&O DiskCleaner function, the O&O DiskStat function as well as the time management function and various extras. The O&O DiskCleaner offers users various cleaning functions. The software removes unnecessary and temporary files that are taking up hard drive space. In addition, O&O Defrag 21 increases the potential security of the files, making them quicker to access. In the O&O DiskStat menu, users can see comprehensive diagrams of the free and used storage space on their data carriers at the click of a button. Use this feature to selectively identify and remove unnecessary files. The practical fragment filter makes it easy to find the most fragmented data on the hard drives. Even locked files can be defragmented without limitation using this program. The free storage memory on the computer can automatically be deleted by the software. Over time, users can see which defragmentation had success. Compared to the previous versions, the defragmentation process is much faster and puts hardly any strain on the computer hardware. In addition, the software prevents too fast fragmentation.

Thanks to a low price and not having a subscription system, O&O Defrag 21 has significantly lower costs compared to other programs. Purchasing, installing and activating the Tune-Up software is smooth and quick. Purchasers benefit from a clearly structured interface. O&O Defrag 21 works on Windows operating systems from Windows 7 upwards and ensures a significant increase in performance. Use on server systems is also possible.

The website has been designed to be clear and user-friendly. In the FAQ section, users can find appropriate answers to most topics and can download manuals, whitepapers and studies from the website. In addition to a free trial version, purchasers have no financial risk as they can make use of a 30-day money-back guarantee.

With a low purchase price of 35 dollars and no subscription, O&O Defrag 21 clearly stands out from the crowd. The defragmentation and optimization program runs exclusively on Windows and can be easily operated thanks to its clear design and intuitive structure. Users can choose from different methods of defragmentation and benefit from individual recommendations as well as useful extras. All connected drives are defragmented and optimized in the background of the operating system without a noticeable performance decrease. With its regular defragmentation, O&O Defrag 21 provides more free memory space on the drives and a permanent increase in performance, while the hardware benefits from longer service life.