Computer Hangs Copying Data from CD-ROM Drive

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Article ID: 132882 - View products that this article applies to.
This article was previously published under Q132882
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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.


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.


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.


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.


Article ID: 132882 - Last Review: January 19, 2007 - Revision: 1.3
  • Microsoft Windows Millennium Edition
  • Microsoft Windows 98 Second Edition
  • Microsoft Windows 98 Standard Edition
  • Microsoft Windows 95
kbfaq kbhardware kbmm kbprb KB132882

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