PRB: MDAC 2.6 SP1 Install Fails After MDAC 2.6 Install on Windows 2000

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Article ID: 303342 - View products that this article applies to.
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If Microsoft Data Access Components (MDAC) 2.6 Service Pack 1 (SP1) is installed immediately after installing MDAC 2.6 RTM, without restarting Windows 2000 between the two MDAC installations, the MDAC 2.6 SP1 installation may fail with the following Windows File Protection dialog box message:
"Files that are required for Windows to run properly have been replaced by unrecognized versions. To maintain system stability, Windows must restore the original versions of these files. Insert your Windows 2000 Server CD-ROM now."
This problem occurs with Windows 2000. It does not occur if Windows 2000 Service Pack 1 or Service Pack 2 are installed.

NOTE: Some products (such as Microsoft SQL Server 2000) install MDAC 2.6, so this problem may occur even if you have not explicitly installed MDAC 2.6.


There are several ways to avoid or work around this problem:
  • If you have installed MDAC 2.6 or SQL Server 2000, restart the system before installing MDAC 2.6 SP1.
  • Install Windows 2000 Service Pack 1 or 2 before installing MDAC 2.6 or MDAC 2.6 SP1.
  • Cancel the Windows File Protection dialog box that appears when you install MDAC 2.6 SP1.
Also note that there is no need to install both MDAC 2.6 and MDAC 2.6 SP1; installing just MDAC 2.6 SP1 is sufficient.


If the restore option is selected, 44 files are restored from the CD that has MDAC version 2.5. If you cancel or ignore the dialog box, and do not insert the CD, the installation succeeds and the Dasetup.log file shows a successful installation.


Article ID: 303342 - Last Review: February 27, 2014 - Revision: 3.1
  • Microsoft Data Access Components 2.6 Service Pack 1, when used with:
    • the operating system: Microsoft Windows 2000
kbnosurvey kbarchive kbdatabase kbprb kbsetup KB303342

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