Symptom: Excessive program load times, slow file transfers
Solution: Disk defragmentation
Disorganized information on your hard drive can sap performance because the computer requires more time to sift through data fragments and bad sectors on the drive. This problem can be cleared up easily (but not especially quickly; defragging can sometimes take hours) using the built-in Windows tool called Disk Defragmenter. You can access this program through the Programs menu in the Accessories or System Tools folder. Simply click the Analyze button to see if your disk drive requires defragmenting, and then click Defragment to begin.
Other options include the free Power Defragmenter, and Diskeeper 2007 (R458 Home edition, R763 Pro, R1526 Pro Premier), which offers more features like complete automation, real-time defragmenting, and InvisiTasking technology, which allows Diskeeper to run in the background without draining resources.