Microsoft KB Archive/132882

= Computer Hangs Copying Data from CD-ROM Drive =

Article ID: 132882

Article Last Modified on 1/19/2007

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APPLIES TO


 * Microsoft Windows Millennium Edition
 * Microsoft Windows 98 Second Edition
 * Microsoft Windows 98 Standard Edition
 * Microsoft Windows 95

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This article was previously published under Q132882



SYMPTOMS
When you are copying a large directory structure from a CD-ROM drive to a local hard disk, your computer may stop responding (hang). You must perform a local reboot to end the copy task and regain control of your computer.



CAUSE
The Windows CD-ROM file system with protected-mode drivers includes a "Read-Ahead" feature that is designed to provide smoother video playback, with faster and more efficient data streaming. The Read-Ahead feature can cause the CD-ROM drive controller to be driven faster than it was designed to be.



RESOLUTION
To prevent this problem, follow these steps:


 * 1) Click the Start button, point to Settings, then click Control Panel.
 * 2) Double-click the System icon.
 * 3) On the Performance tab, click File System.
 * 4) Click the CD-ROM tab.
 * 5) In the Optimize Access Pattern For box, click the setting that matches the CD-ROM drive you are using. Click OK. Restart the computer when you are prompted to.
 * 6) If steps 1-5 do not solve the problem, repeat steps 1-4. In the Optimize Access Pattern For box, click No Read Ahead. Click OK. Restart the computer when you are prompted to.



MORE INFORMATION
The following table describes the Optimize Access Pattern For settings:

  Setting               Behavior ---  No Read Ahead         Read ahead 0 bytes Single-speed drives  Read ahead 50K bytes Double-speed drives  Read ahead 100K bytes Triple-speed drives  Read ahead 150K bytes Quad-speed drives    Read ahead 200K bytes

If you are not sure of your CD-ROM drive's transfer rate, please consult the drive's documentation or manufacturer.

Additional query words: hwcds

Keywords: kbfaq kbhardware kbmm kbprb KB132882

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