Missing Library Reference in collection

[paulzak]

I've developing an Excel program in Office 2007 running Vista (64). I found when testing the file on a user's XP machine that the following reference is problematic. I seem to have a newer or diff. reference, I guess based on the OS being run.

(VISTA) Microsoft ADO Ext. 6.0 for DDL and Security (File: msadox.dll)
(XP) Microsoft ADO Ext. 2.8 for DDL and Security (File: msadox.dll)

My reference causes code errors for Left(x) and some other basic code. If I manually change my reference in the file while on-site running XP, the code then runs fine. I'm trying to avoid having to develop/support 2 versions of this app.

My question is whether there is some way I can download the 2.8 reference to my VISTA machine, set my file to use it, and thus my distributed file would run w/o error on XP user's PC. But I find nowhere to download such Library References from Microsoft. (Perhaps messing with the .dll file would destabilize Office/VISTA?)

NOTE: On my VISTA 64 machine, the dll file exists under both C:\Program Files (x86) and C:\Program Files folders.

I see the following options:

1) Re-link the reference to the dll file under the \Program Files folder (not the "x86" folder, which I assume is for Vista 64)

2) Add code that will detect the "Missing" reference and insert the local one (I've seen example code on the Web.)
Example: http://www.vbaexpress.com/kb/getarticle.php?kb_id=267

3) Develop the file on an XP machine, matching the user's machine.

Am I missing anything easier and more solid?
Thanks in advance.

p.s. I don't think I want to get into late or early binding, which I don't understand but have read doing so would eliminate the need for any references. I also don't want to pass along code with binding in it to another developer who may also be unfamiliar with binding.

[Leith Ross]

Hello paulzak,

Windows Vista is not 100% backward compatible with Windows XP or any earlier versions of WIndows. This was the first OS to break with the long standing tradition of backward compatible software.

Of the options you listed, number 3 is the easiest. Number 2 is not as easy as it sounds. You would need to determine if the system has the needed library and if not load it in. Doing this on your own personal machine isn't so bad, but loading software onto another machine is challenging due to security issues and access rights. As for Number 1, relinking DLL references is not an option I would choose. Making a mistake here could leave the system fubar. Something the end user would not appreciate.

[DonkeyOte]

The library in question formed part of what was / is known as MDAC (Microsoft Data Access Component) but which has now become WDAC ... from a quick Google the implication is that 2.8 is not available for 64-bit machines but you might want to investigate further just in case.

[paulzak]

Thank you both for very informative replies. I've found that because of unchangeable MACRO security settings on site (checkbox granting access to Project's Objects is not checked) I can't even run any code to merely determine whether a reference is missing and if so halt the program and notify the user.

Since my XP machine finally crashed months ago after years of good service, per option 3 above, I may consider purchasing an XP machine for this development work (and other reasons...like I really HATE Vista) and/or may just have to go on-site with file each update, reset the reference, save file and distribute it. What a hassle.

Mr. Ross, a final question: Will Windows 7 be any more backwards compatible than Vista?

[Leith Ross]

Hello paulzak,

You will be relieved to know that Microsoft has extended service for XP to the year 2014! This is because of the loyal following of Windows XP, which has been the most successful OS Microsoft has created. Because of this, Windows 2007 has a Windows XP Productivity mode. This is actually a virtual machine version of the the XP operating system. You can run XP and Winfdows 7 at the same time!

[paulzak]

I've read about this. Thanks for the reminder.

As usual with IT, "the devil is in the details": I've heard that you must buy a higher level of Win 7 (not ALL version have this) and then you must download additional files, though free, to run/use this feature in the higher version. So, I'm curious to see just how "easy" and effective this feature is to use. Often, it's NOT even mentioned in many sites' materials about Win 7 functionality, which surprises me because it seems like a HUGE and valuable feature...at least to me. Either many folks don't care about it, or it doens't really work as well as Microsoft says it does. (I'm not an OS expert.)

So, I'm cautiously waiting to hear more from folks specifically about this feature.

[romperstomper]

One thing I can say is that your machine needs to support hardware virtualisation (in the BIOS) or you cannot use XP mode. There are if course other VM solutions, but you would need a licenced copy of XP.
re your original question, I would probably recommend late binding as the easiest solution, personally.