Invalid Class String message

Question

My operating system is Vista Ultimate 64 Bit. With my Canon digital camera I got software containing a programme called ZoomBrowser EX. Each time I try to run this program a get a 'Critical Error' message saying 'Invalid Class String'. What is the cause of this and how do I fix it? I have contacted Canon but they tell me that it is a Microsoft problem.

Answer 1

Hi Bev-stan,

Thank you for posting on the forum.

Quick questions, have you tried uninstalling the program and reinstalling it again? Do you have any programs running in the background of Vista when you did your install? What I can suggest that you try is to uninstall your program > use the Windows Installer CleanUp Utility > Perform a Clean Boot of Vista >  then reinstall your software.

Here’s a couple of link to articles that could be of help fixing your problem.

Description of the Windows Installer CleanUp Utility

http://support.microsoft.com/default.aspx/kb/290301

How to troubleshoot a problem by performing a clean boot in Windows Vista

http://support.microsoft.com/kb/929135

For your future reference, please be advised of Microsoft’s

THIRD PARTY SOFTWARE DISCLAIMER

Using Third Party Software, including hardware drivers can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the use of Third Party Software can be solved. Using Third Party Software is at your own risk.

Hope that helps, please post back and let us know if that worked for you.

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JohnD

Microsoft Answers Support Engineer

Visit our Microsoft Answers Feedback Forum and let us know what you think.

Answer 2

sorry, I can not understand your question. You have Windows 7. My previous response on April 9, 2017, provides some details on Windows 7 and the ZoomBrowserEX software.

Answer 3

So  ho can  halp me   I  do have  window 7