There are some situations where your computer's hard drive becomes fragmented and needs to be cleaned up to help it's speed and performance. You can do this defragment procedure yourself. It can take several hours for the computer to complete this task, so it's a good idea to plan accordingly. It's usually best to start in in the evening and let it run during the night.
Click on the START > My Computer and then find your C: drive and right-click it and select Properties.
Click the Tools tab, and then the Defragment Now button as shown here
Then press the Analyze button. The computer will then scan your hard drive and tell you if it needs to be defragmented. This step should take less than 20 minutes.
When you are ready, you can click the Defragment button, and the computer will proceed to defragment the hard drive. This step will take the longest, so you might have to leave your comptuer for several hours and let it do it's job.