Disc fragmentation slows down the speed of computer. De fragmentation should be carried at regular interval(at least once in a month). If a large number of files are added,new programs or a new version of Windows is installed or if the free space comes below 15% De fragmentation should be carried out .
Steps for disk de fragmentation
start > All Programs > Accessories >System Tools > Disk De fragmenter
Select the drives that you want to analyze
Select the file for defragmetation
when defragmentation completes it displays the results
Then click View Report
For closing View Report dialog box, click Close.
For closing the Disk Defragmenter utility, click the Close button on the title bar of the window.