Sony PCG-GRX690P - Manual (Page 166)

VAIO Computer Quick Start
166
To defragment a partition
1 Back up all files you want to save.
2 From the Start menu on the Windows® taskbar, point to All Programs,
Accessories, System Tools, and then click Disk Defragmenter. The Disk
Defragmenter dialog box appears.
3 Select the drive you want to defragment from the list, and click Defragment.
See the Microsoft® Windows® operating system Help guide for more
information on defragmenting.