ARTICLE-ID:Q142687 TITLE :Windows NT 4.0 Not Able to Read Some Compact Discs PRODUCT :winnt PROD/VER:4.00 OPER/SYS:WINDOWS KEYWORDS:kbhw --------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation versions 4.0 - Microsoft Windows NT Server versions 4.0 --------------------------------------------------------------------------- SYMPTOMS ======== When you attempt to read or copy files from certain compact discs to your hard drive, you get the following error message: Cannot copy : Error performing inpage operation. The same files could be copied by earlier versions of Windows NT, or by other operating systems, and other compact discs work correctly. CAUSE ===== This error is caused by the compact disc file system (CDFS) not quite correctly recognizing the allocation size of a file on media of a block size different than the physical sector size of 2048 on a compact disc (for example, less than indicated per ISO 9660). CDFS tries to generate sector- aligned reads regardless of whether it is doing that reading beyond the mapped range of the file. WORKAROUND ========== Obtain the following update or wait for the next Service Pack. ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40 /hotfixes-postSP1/cdfs-fix STATUS ====== Microsoft has confirmed this to be a problem in Windows NT version 4.00. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Product Support Services for more information. KBCategory: kbhw kbbug4.00 KBSubcategory: ntdriver nthw Additional reference words: compact prodnt 4.00 ============================================================================ THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1996.