Here are instructions to perform a Disk Defragmenter from Windows. The Disk Defragmenter is a tool that reorganizes and regroups data to help improve the performance of the computer and is beneficial to optimize the performance of the external hard drives.
On the keyboard, press the Windows Key () + E
Once the (MY) Computer / This PC is open, hover over the drive you want to perform the Defragmentation and right-click on the Seagate drive.
Click on Properties
Click on Tools
Click on Defragment now (Optimize in Windows 8/8.1/10)
To determine if the disk needs defragmentation, select Analyze disk.
To start the defragmentation, click on Defragment disk
Click Close when it is concluded.