De-fragmenting a hard drive improves the performance of a hard drive and it is recommended to de-fragment your hard drive from time to time as shown in this video. In Windows 7 you can use the Disk De-fragmentation tool. To do this go to the start menu and open the Control Panel. In the right column select the Performance Information and Tools. Now in that window in the left hand column select the Advanced tools option. In that new window scroll down to the Open Disk De-fragmenter link. Click it to open the Disk De-fragmenter tool. There is an option to analyze the disk which gives you the status of fragmentation in your hard drive. You can also choose to de-fragment your disk by selecting that option over there. This video shows you how to de-fragment your hard disk in Windows 7 using Disk De-fragmenter tool.