A technician is called to troubleshoot a Windows file server. The technician is told that it takes longer than usual to open documents and, at times, documents will not open at all. The technician notices all the hard drive activity lights in the server room are on and appear normal. The technician then checks the Event Viewer on the server and discovers an unusual number of hard disk errors.
Which of the following command line tools should the technician use to find and correct these errors?