Computer Hangs Copying Data from CD-ROM Drive

ID: Q132882

The information in this article applies to:

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. 


Keywords          : kbhw kbmm win95 win98 cddrive 
Version           : 95
Platform          : WINDOWS 
Issue type        : kbprb

Last Reviewed: March 3, 1999