There are several ways to perform a defragmentation of your hard drive  in Windows XP.   Simply open the Start menu, then Programs, then Accessories.  Click on ”System Tools” then click on the icon for Disk Defragmenter.   Generally Drive or Local Disk C:  will be the one you want to highlight; if it is already highlighted simply click on “Defragment”, and it will analyze your drive, and immediately defragment it if there are no errors Scandisk needs to fix.    A second way to defragment is to locate the My Computer icon, double-click on it and then when its window opens, right-click on the C:  drive.   Go to properties, left-click on it and a window with tabs will open.   Click on the Tools tab, and that will open to reveal both Scandisk (error-checking) and Defragmenter (defragmentation).  Click on “defragment now” and the defragmenter window will appear displaying all existing drives on your computer.   To run Scandisk, which checks your drive for errors and also fixes them, follow the same procedure.  Simply click on “check now” to run error-checking, or Scandisk.

A third way to run Disk Defragmenter, or any executable program, for that matter, is to schedule it to run when it is most convenient, with Task Scheduler.   Left-click on the Start Menu Icon, then go to Accessories, click on System Tools, then on Scheduled Tasks.  Click on an already queued task, or the icon that reads, “Add Scheduled Task,” and follow the directions from the Wizard.