In Windows 10 and later, however, automated optimization is turned on by default (via Help Desk Geek). Theoretically, this should eliminate the need to manually defrag a hard drive, but the ...

As with the defragment utility built into Windows, this freebie analyzes your hard disk, shows you the results, and then lets you decide whether to defragment.

Three more thoughts on the whole Disk Defragmenter debacle. Was it really to blame? How important is a disk defragger, anyway?

As files become increasingly fragmented on a hard drive, the machine's overall performance can take a hit. That's where Windows' defragging comes in.

To recap, my otherwise blazing PC was suffering from inexplicable (and temporary) slowdowns. After months of troubleshooting efforts, the culprit turned out to be Disk Defragmenter.