6. Click Defragment Now again to start a disk-defragmentation process.On the Windows 8 or Windows 8.1 operating system, do the following:1. Close any programs that are currently running and close any open windows.2. On Windows 8, open File Explorer and click Computer. On Windows 8.1, open File Explorer.3. Right-click your C drive entry and then click Properties.4. Click the Tools tab and then click Optimize.5. Click Optimize in the Optimize Drives window that is displayed to start a disk-defragmentation process.Insufficient memorySymptom: Insufficient memoryIn general, the more memory that is installed, the better the Windows operating system runs.Action: Install additional memory. For information about purchasing memory, see Chapter 11 “Gettinginformation, help, and service” on page 113. For step-by-step instructions on installing memory, see“Installing or replacing a memory module” on page 45.If these actions do not correct the problem, run Lenovo Solution Center. If you need technical assistance,see Chapter 11 “Getting information, help, and service” on page 113.Printer problemsSymptom: The printer does not work.Actions: Verify that:1. The printer is turned on and is online.2. Paper is loaded correctly.3. The printer signal cable is securely connected to the correct parallel, serial, or USB connector on thecomputer.Note: Non-IEEE-approved printer signal cables might cause unpredictable problems.1. Any device drivers and other software that came with the printer are correctly installed.2. You have assigned the printer port correctly in your operating system, application program, or BIOSsettings. For more information about BIOS settings, see Chapter 7 “Using the Setup Utility program”on page 83.If the problem persists, run the tests described in the documentation that comes with your printer. If youcannot correct the problem, have the computer serviced. See Chapter 11 “Getting information, help, andservice” on page 113.Serial connector problemsUse this information to troubleshoot the serial connector and devices attached to the serial connector.Symptom: Serial connector cannot be accessed.Actions:• Make sure the serial cable is securely connected to the serial connector on the computer and to the serialdevice. If the serial device has its own power cord, make sure it is attached to a properly groundedelectrical outlet.110 ThinkCentre M73 User Guide