SUMMARY
Starting with Microsoft Data Access Components (MDAC) version 2.6, MDAC no longer contains Jet components. In other words, MDAC 2.6 and 2.7 do not include Microsoft Jet, 
Microsoft Jet OLE DB Provider, and the ODBC Desktop Database Drivers. 
MORE INFORMATION
How to Install the Jet 4.0 Components
If you are installing MDAC 2.6 or 2.7, and also need to install the Jet components, you can download a redistributable version of Jet 4.0 Service Pack 3 (Jet40SP3_Comp.exe). 
See the instructions later in this article for the location of this download and instructions on how to install it. 

Jet40SP3_Comp.exe is a complete set of Jet 4.0 components for Microsoft Windows 95, Microsoft Windows 98, and Microsoft Windows NT version 4.0. Jet40SP3_Comp.exe gives you 
the complete Jet 4.0 components up to Service Pack 3 (SP3). This is the same version of Jet that ships with Microsoft Windows 2000 and Microsoft Windows Millennium Edition (Me).

NOTE: You should only install Jet40SP3_Comp.exe when Jet 4.0 is not already installed by your operating system, an application, or 
Microsoft Access Data Components (MDAC) 2.5 Service Pack 1 (SP1) or earlier. Before installing Jet40SP3_Comp.exe, you need to install MDAC 2.6 or later. 

To install the Jet 4.0 components, follow these steps: 
Download MDAC 2.6 or later and the redistributable Jet 4.0 Service Pack 3 from the following Microsoft Web site:
http://msdn.microsoft.com/dataaccess

In Windows Explorer, double-click the mdac_typ.exe file you downloaded in step 1 to begin the MDAC setup.
Restart your computer.
In Windows Explorer, double-click the Jet40SP3_Comp.exe you downloaded in step 1 to begin the Jet 4.0 setup.
Restart your computer.
The computer now has the Jet 4.0 SP3 components. To install the latest Jet 4.0 Service Pack, see the following article: 
239114 ACC2000: Updated Version of Microsoft Jet 4.0 Available in Download Center 

The ODBC Desktop Drivers and Visual FoxPro ODBC driver, which no longer ship with MDAC 2.6, are shipped with the Microsoft Windows 2000 operating system 
(which contains MDAC 2.5). Microsoft Windows Millennium Edition (Me) also ships with MDAC 2.5.

Microsoft Windows XP also contains the ODBC Desktop Drivers and Visual FoxPro Driver. For Microsoft Windows NT and Microsoft Windows 9x, MDAC 2.5 or an earlier version 
will need to be installed to obtain these drivers.

These ODBC Desktop Drivers and Visual FoxPro ODBC driver also ship with Microsoft Office 2000 and Microsoft Office XP. The Visual FoxPro ODBC driver can also be obtained at 
the following Web site: 
http://msdn.microsoft.com/vfoxpro/downloads/odbc.asp

REFERENCES
"The MDAC 2.5 Stack and Windows File Protection" white paper contains a full list of the components that are shipped with MDAC 2.5, along with a discussion of Windows File Protection. 
Refer to this white paper for more information on the Jet dynamic-link libraries (DLLs) that are shipped in MDAC 2.5 and that are no longer a part of MDAC 2.6 and 2.7: 
http://www.microsoft.com/data/mdacwfp.htm

