Frequently asked questions about the installation of Microsoft Data Access Components (MDAC)

Frequently asked questions

Q1: What is MDAC?

A1: MDAC contains key technologies that enable Universal Data Access. Data-driven client/server applications that are deployed over the Web or over a local area network (LAN) can use these components to integrate information from a variety of sources, both relational, such as SQL, and non-relational. These components include Microsoft ActiveX Data Objects (ADO), OLE DB, and ODBC.

Q2: What are the system requirements for installing the versions of MDAC that are listed in the "Applies to" section?

A2: The minimum system requirements that you must have to install and to use the versions of MDAC that are listed in the "Applies to" section are as follows:

• A 486 or faster processor.
• Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows NT 4.0 Service Pack 5 or later, Microsoft Windows 2000, or Microsoft Windows Millennium Edition
• Microsoft Internet Explorer 4.01 Service Pack 2 or later.
• Distributed Component Object Model (DCOM 95), originally provided with Internet Explorer 4.01 Service Pack 2.
• Administrator permissions on the computer (if you are using Windows NT or Windows 2000).
• Approximately 20 megabytes (MB) of free disk space on the system drive.
• You may have additional requirements depending on the version of MDAC that you are using.

Q3: How do I install the versions of MDAC that are listed in the "Applies to" section?

A3: To install the versions of MDAC that are listed in the "Applies to" section, run the MDAC_Typ.exe executable program. There are also switches that you can use with the MDAC_Typ.exe file to meet different requirements. The following table lists the switches that are available.Q4: What is the Dasetup.exe file?

A4: Dasetup.exe is the setup engine that is used for MDAC 2.5 and the versions of MDAC that are listed in the "Applies to" section. Dasetup.exe performs all the dependency checks and the installation of files, and also sets the registry values. Depending on the status of the installation, Dasetup.exe returns the values shown in the following table.Q5: Where is the Dasetup.exe file installed?

A5: Dasetup.exe is installed in the following folder:
System Drive:\Program Files\Common Files\Microsoft Shared\Dasetup

Q6: What are the switches for Dasetup.exe?

A6: The following table shows the switches that are available for Dasetup.exe.Q7: How do I install Dasetup.exe by using all these switches?

A7: The following are examples of how to use these switches:

• To run the versions of MDAC that are listed in the "Applies to" section installation silently, without any dialog boxes, use the following command line:
  MDAC_TYP.EXE /q:a /c:"dasetup.exe /q"
• To run the versions of MDAC that are listed in the "Applies to" section installation silently, without automatically restarting the computer, use the following command line:
  MDAC_TYP.EXE /q:a /c:"dasetup.exe /q /n"

Q8: What is Rollback?

Caution Rollback might cause pre-existing applications to function incorrectly.

A8: The MDAC Setup program now includes a Rollback feature. This feature allows you to roll back to the earlier version of MDAC that was installed on the system before you installed the versions of MDAC that are listed in the "Applies to" section. When you run the versions of MDAC that are listed in the "Applies to" section Setup program, the Setup program does the following:

1. Scans your system before installing any new files to determine which MDAC files are currently installed.
2. Caches a copy of all the currently installed MDAC files that will be replaced by the new version.
3. Installs the new files.

If a Rollback becomes necessary, you can restore the cached versions of the previous MDAC files.

Q9: What can I do if I must roll back to an earlier version of MDAC?

Caution Rollback might cause pre-existing applications to function incorrectly.

A9: To initiate Rollback, run the Dasetup.exe file with the following command line:
dasetup.exe /u

Note The Dasetup.exe file is already installed on the computer. See question 5 to determine where the Dasetup.exe file is installed.

Q10: Can Rollback always roll back the versions of MDAC that are listed in the "Applies to" section to the earlier version without any problems?Caution Rollback might cause pre-existing applications to function incorrectly.

A10: No. For example, Rollback might fail after you reinstall the versions of MDAC that are listed in the "Applies to" section for the second time.

Q11: What can I do if Rollback fails, and the versions of MDAC that are listed in the "Applies to" section DLLs are now damaged?

Caution Rollback might cause pre-existing applications to function incorrectly.

A11: Select the appropriate method for your operating system based on the following information:

• Microsoft Windows 2000 Install Microsoft Windows 2000 Service Pack 1 (SP1). Windows 2000 SP1 installs MDAC 2.5 SP1. You can install the versions of MDAC that are listed in the "Applies to" section after you install Windows 2000 SP1. To download Windows 2000 SP1, visit the following Microsoft Download Center Web site:
  http://www.microsoft.com/downloads/Search.aspx (http://www.microsoft.com/downloads/Search.aspx)
• Microsoft Windows NT 4.0, Microsoft Windows 95, or Microsoft Windows 98 Use the Component Checker tool to reconfigure the version of MDAC. Then you can install the versions of MDAC that are listed in the "Applies to" section. For more information about Component Checker and about how to download the tool, visit the following Microsoft Developer Network (MSDN) Web site:
  http://msdn2.microsoft.com/en-us/data/aa937695.aspx (http://msdn2.microsoft.com/en-us/data/aa937695.aspx)
• Microsoft Windows Millennium Edition Until a Windows Millennium Service Pack is released, currently the only options that are available are to reinstall or to repair the operating system. Either option installs MDAC 2.5. After you install MDAC 2.5, you can install the versions of MDAC that are listed in the "Applies to" section. For the latest information about service packs and downloads, visit the following Microsoft Download Center Web site:
  http://www.microsoft.com/downloads/Search.aspx (http://www.microsoft.com/downloads/Search.aspx)
  .

Q12: How does Application Registration help during Rollback if a Rollback becomes necessary?

Note See questions 8 through 11 before you try to roll back the versions of MDAC that are listed in the "Applies to" section.

A12:The versions of MDAC that are listed in the "Applies to" section incorporate Application Registration. This feature reduces the risk that an application will stop functioning if MDAC performs a Rollback. This allows currently installed applications to register themselves with the Setup program. The MDAC Setup program lists the registered applications, and flags the applications that may not function correctly after a Rollback.

Q13: How do the versions of MDAC that are listed in the "Applies to" section Setup program handle files that are in use by the operating system?

A13: The versions of MDAC that are listed in the "Applies to" section include a Detecting In-Use Files feature. When you run the versions of MDAC that are listed in the "Applies to" section Setup, the Setup program does the following:

• Detects the MDAC files that are in use during the installation.
• Queries the system to determine which processes are using the files.
• Prompts you to shut down these processes to avoid having to restart the computer after the installation is complete.

Q14: Does the Detecting In-Use Files feature support version checking?

A14: No. The Detecting In-Use Files feature may unnecessarily prompt the user to shut down an application to avoid a restart. For example, while installing the versions of MDAC that are listed in the "Applies to" section on a computer that has a newer version of Oledb32.dll installed that is later than version 2.6, if an application is using OLE DB, the Setup program may prompt the user to shut down that application. In this case, you might not have needed to close the application. This behavior occurs because the Dasetup.exe engine uses version checking while installing the MDAC files. Version checking prevents the older version file from being installed over its newer counterpart.

Note See question 4 for more information about the Dasetup.exe program.

Q15: Do all the processes have to be shut down during installation?

A15: No. To continue the Setup program, click Next. However, after a successful installation, you may have to restart the computer.

Q16: I use Windows File Protection (WFP) for important system files. Will this be a problem when I install the versions of MDAC that are listed in the "Applies to" section?

A16: No. the versions of MDAC that are listed in the "Applies to" section Setup program ensures seamless installation of system-protected MDAC files on computers that are running Windows 2000 or Windows Millennium Edition. Additionally, the versions of MDAC that are listed in the "Applies to" section Setup program prevents the versions of MDAC that are listed in the "Applies to" section files from being overwritten if a computer is running Windows NT 4.0, Windows 95, or if a computer that is running Windows 98 is upgraded to Windows 2000 or to Windows Millennium Edition.

Q17: Is there a software development kit (SDK) for MDAC 2.6?

A17: Yes. This is the first release of the MDAC SDK that uses the Windows Installer. The SDK Setup program contains a generic Setup for authoring the SDK merge modules. This feature ensures a standard format for different SDK combinations. Different SDK combinations include the MDAC 2.6 SDK, the Platform SDK, and the MSXML 2.5 SDK.

Q18: What has been excluded from the MDAC 2.6 stack?

A18: The following components are no longer included in MDAC 2.6:

• Microsoft Jet, the ODBC Desktop Databases drivers, and Jet OLE DB provider.
  Note Five Jet Expression Services DLLs are still included, because the MSDataShape Provider and the OLE DB Cursor Services depend on the DLLs. The five DLL files included are as follows:
  • Vbajet32.dll
  • Expsrv.dll
  • Msjtes40.dll
  • Mswdat10.dll
  • Mswstr10.dll
• Microsoft Visual FoxPro ODBC driver.
• OLE Automation DLLs.

Q19: What other new features are included in MDAC 2.6?

A19: The following new features are included in MDAC 2.6:

• Minimizing the Setup program dependencies to reduce the number of times that you must restart the computer.
• Providing the end-user license agreement (EULA) in a rich text format (.rtf).
• Ensuring that only a single instance of the MDAC Setup program is allowed to run at the same time.

For the latest information about MDAC, visit the following Microsoft Web sites: