What are some alternatives?
When comparing Defraggler and Windows Disk Defragmenter, you can also consider the following products
UltraDefrag - UltraDefrag is an open source disk defragmenter for Windows.
PerfectDisk - PerfectDisk reduces total IOPs by 15-40% and reduces disk latency up to 80%.
MyDefrag - MyDefrag (previously JkDefrag) is a disk defragmenter and optimizer (a maintenance utility to make...
IObit Smart Defrag - Disk defrag your Windows with Smart Defrag freeware, Your first choice for defragging windows 10, 8, 7, XP and Vista. Download Free disk defragmenter now!
Auslogics Disk Defrag Touch - The smart way to defragment a touch-screen computer running Windows.
WinContig - Freeware file defragmentation tool.