If you want to speed up your computer or optimize its performance, I am sure that you have tried to defragment disk once or more. It is true that defragmentation can help improve computer performance. But, during the defragmentation, some may have encountered certain problems. So, in this article, I will introduce the common methods to solve this problem.

If the system is reminding you that there is "chkdsk" running, it cannot defragment the disk. If this happens, you can solve it as follows:

Before defragmentation, you should clear up the disk. Click "My Computer", right-click the drive needs to defragment and click "Properties"-"General" to choose disk, take C disk for example, in the dialog box of "Disk Cleanup for (C:)", you can tick the files to delete. And you can check these files by clicking "View Files". Then, click "OK" to clean up the C disk.

Secondly, you should scan the disk ahead of defragmentation. Also in the "Properties" tab, click "Tools"-"Check Now"-"Start". After finishing the scan, you can exit this dialog box. Then, in this stage, you have to make sure that you have closed down all the running programs, the real-time virus monitor and screen saver in particular.

Now, you can start defragmentation. In the "Properties" tab of the disk you want to defragment, click "Tools"-"Defragment Now"-"OK". The system will remind you after completing it.

Be careful that, you should not read and write any data during this process but just let your computer to finish it, because the computer is vulnerable to go crushed by any read-write operation. If it is hard to end defragmentation, you have to defragment it in the "Safe Mode".