Frequently asked questions
Last updated on Mar 25, 2025
Below you can find answers to common questions about UltraDefrag use.
Some of my disks don’t show up in the graphical interface. How to fix that?
If you have multiple disks connected to your computer they all might not fit into the list of disks due to space constraints. You have 2 easy options, however, to fix the problem. First of all, you can use a scrollbar located on the right side of the list to scroll the list and thus access all your disks. Alternatively you can enlarge the list by dragging down its bottom border.
Do I need to defragment solid state drives (SSD)?
While solid state drives have no mechanical parts inside and thus no data access delays induced by moving parts, they still do suffer from fragmentation, because heavily fragmented files significantly drop down performance of the file system itself. Slightly fragmented files, on the other hand, do not affect SSD performance much. By default, UltraDefrag excludes all files having less than 20 fragments during SSD defragmentation. Additionally, the latest version of UltraDefrag uses the TRIM command to further improve SSD performance and prolong the life span of your SSDs. Check our article about SSD preferences for more information.
Can I defragment multiple disks simultaneously?
Yes, you can easily do it using multiple instances of UltraDefrag. Please note, however, it does make sense only if the disks are located on separate physical drives, because simultaneous defragmentation of disks located on the same physical drive naturally slows down the processing instead of speeding it up.
How to move all files and folders to the beginning of a disk?
To move all files and folders to the beginning of a disk check Deep action in the preferences dialog and then perform the full optimization of the disk.
How to defragment free space on a disk?
To defragment free space on a disk, perform the disk optimization.
How to defragment a disk without a drive letter assigned?
To defragment a disk which does not have a drive letter assigned, temporarily assign a drive letter to the disk and then defragment it. To fully automate the process you can use the system diskpart utility.
Why the disk processing slows down at times?
The disk processing progress indicator measures disk space, so it advances quite quickly when UltraDefrag processes large files and slows down when small files get processed.