DLL Hell?

Posted on 2011-04-21
Last Modified: 2012-05-11
I think this is a DLL problem, but i'm not sure.....

We have a mixture of XP and windows 7 pcs around the office. Normally I develop our application on a Windows XP machine and create a .ACCDE file for the clients to use.

Today I used a Windows 7 pc to create a .ACCDE what I found is that other Windows 7 clients can open this file without a problem. However, XP clients cannot now open the ACCDE or ACCDB. They get an error:

"Class does not support automation, or expected interface is missing" This error occurs at a line in my code where an ADODB.connection is declared.

I am surprised that the .ACCDB also now exhibits this behaviour on my original pc. What might have caused this? I have checked that I have no missing references. Everything looks ok there.
Question by:TownTalk
    LVL 84

    Accepted Solution

    Are you using a ADO to work with data on that Windows7 machine? If so, then I'm betting that Win7 machine has been updated to Service Pack 1, which introduces this bug in apps that use ADO to manipulate data:

    The "fix" is to either (a) uninstall SP1 and then recompile the app or (b) change all ADO calls to Late Binding. I believe there's also a hotfix that can be installed on CLIENT machines to remove this error, but most feel that is too difficult to manage and instead use one of the methods above. I keep a vmWare session of Win7 with NO SP1 installed just to be sure I can properly compile any apps which use ADO.


    Author Comment

    Yes this is new Windows 7 machine that we only bought last week. I installed all the updates, including Service Pack 1. Since I posted my original question, I dug out a backup copy of the .ACCDB and verified that the references hadn't changed.

    So I think you are correct. So I will avoid using this machine for development until I hear that this has been fixed.

    Thanks for your help.


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