The minute your computer's hard disk starts to act flaky, make sure you have an up-to-date backup. Then you can do some simple diagnostics and repairs. Both Windows and Mac OS come with built-in hard-disk utility software that scans your hard disk for errors and attempts to fix them.
Computer problems? Maybe the hard drive has bad sectors
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Double-click on My Computer to open the My Computer window.
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Select the disk that you want to diagnose and repair.
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Choose Properties from the File menu. You should see the Properties window for the drive that you selected.
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Choose the Tools tab.
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Click the Check Now button under Error Checking Status.
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Depending on your version of Windows, choose either "Thorough" or "Scan for and Attempt Recovery of Bad Sectors."
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Click on Start.
