You can use Defraggler to defragment any hard drive, but it's not always necessary. Hard drives tend to get fragmented over time, as old files are deleted and Windows uses these scattered free areas to write portions of new files.
If you're working with a relatively new PC, if you've defragmented your drive recently, or if you don't use your PC much, you may not need to defragment. Use the Analyze feature to determine how fragmented your drive is first.
Note: Alternatively, you can also search for specific types of files to defragment.
To analyze a drive:
Interpreting the results:
To interpret the results, you can do one or more of the following:
It's up to you whether the hard drive needs defragmenting. There's no harm in defragging a drive using Defraggler, but it will take time and some processing power.
Also, hard drives have a finite lifespan. Eventually, they wear out from use. It makes sense to defrag when you need to and otherwise to keep an eye on what Defraggler reports back.