DAO compatibility in Windows Vista 64

[Aeneas32]

An older application I have includes a version of DAO 3.5 which it detects during installations needs to be installed on Windows Vista 64 Ultimate.
However, the setup for this DAO fails to install on Windows Vista 64.

I have read that there is a version of DAO which is included with Windows Vista 64, but it must be incompatible with this older application.
Is there any way to provide DAO compatibility within Windows Vista 64 ?

[akhileshbc]

Welcome to VBForums.com

Try upgrading to ADO...

[akhileshbc]

Check this also:
http://www.vbforums.com/showthread.php?t=416218

[Aeneas32]

Welcome to VBForums.com

Try upgrading to ADO...

Are you saying that ADO could be installed on the PC to allow this old application to work ?
I do Not have access to the source code of this application.

[vb5prgrmr]

You need to install MDAC prior to ??? version 2.5/6. I think... Okay, you need to install (If you can) MDAC 2.5 to make dao 3.6/jet 4.0 work. You can find it at MS



Good Luck

[Aeneas32]

You need to install MDAC prior to ??? version 2.5/6. I think... Okay, you need to install (If you can) MDAC 2.5 to make dao 3.6/jet 4.0 work. You can find it at MS
Good Luck

I found mdac_typ.exe on the Microsoft site but that installer does not seem to work on Windows Vista Ultimate 64.
It seems to terminate immediately.

[si_the_geek]

Welcome to VBForums

Thread moved to 'Database Development' forum (the 'VB6' forum is only meant for questions which don't fit in more specific forums)


DAO is also seriously out of date. We have been told by Microsoft for over 11 years (since VB6 was released) to not use it, and for several years it has been officially obsolete (which is much worse than "unsupported").

It is not supported on 64 bit versions of Windows, but you might be able to find a way to make it work... one potential way (which will be expensive) is to install MS Access, but I'm not sure if that will work.


As you do not have the source code for the program, you cannot change it to use ADO (as it should have been before), so if you can't get DAO to work you will need to re-write the application.

[dilettante]

You cannot install any MDAC release into Vista or Windows 7 (whether 32-bit or 64-bit). MDAC has been replaced by DAC, and these are protected system components you cannot overwrite with old MDAC versions.

If you really want to continue using DAO instead of rewriting for ADO you might consider using DAO 3.6 instead. This would probably involve the fewest program changes though you might be forced to use Jet 4.0 instead of Jet 3.5 with it. As far as I can determine Jet 4.0 can still work with an old "Access 97" MDB file - at least it can from ADO.

Your application installer will need to deploy DAO 3.6 since it is not part of DAC 6.x (Vista and later).

Note that DAO36.DLL needs to be deployed to a folder named:

C:\Program Files\Common Files\Microsoft Shared\DAO

Most application packagers should be aware of this and choose the corerct location automatically. Some are not so smart.

The VB6 SP6 merge module for DAO 3.6 is "aware" of this and the PDW seems to be as well. If using a 3rd party packager you may want to verify it. System32 is not the correct location for this library.

[dilettante]

As you do not have the source code for the program, you cannot change it to use ADO (as it should have been before), so if you can't get DAO to work you will need to re-write the application.

I missed that!

I think you're doomed. A rewrite from scratch might be your only option.

[Aeneas32]

I missed that!

I think you're doomed. A rewrite from scratch might be your only option.

Any possibility for OS virtualization, or is MDAC strictly not having 64 bit Windows ?
Here is a MSDN page which talks about the installability of MDAC on various OS's.
It appears to have been written before Vista was released and does not mention it.
After your reading this, I would like to know what my chances are.
http://msdn.microsoft.com/en-us/library/ms810805.aspx
What is the big difference between 2.8 and 2.5 ?

[si_the_geek]

You don't want MDAC (which you can't install anyway, as implied by your link, and explicitly stated by dilettante), you want DAO - which has been separate for many years.

DAO is not supported on 64 bit OS's. Your best chance (assuming that your program uses DAO 3.6) is to follow dilettante's suggestion in post #8 - but it is certainly not guaranteed to work.

[Aeneas32]

It looks like a file I received from ATI tools set during their All In Wonder heyday years back called "DAO.EXE" installed the necessary files to create the
C:\Program Files\Common Files\Microsoft Shared\DAO directory
and that seems to have made this old application work.

I did not think it had worked since running that executable gave an error
"Error 1911.Could not register type library for file C:\Program Files\Common Files\Microsoft Shared\DAO\Dao360.dll."
Perhaps the old application simply looks explicitly for that pathname.
I could not find the DAO download on the Microsoft web site.