Some client machines unable to install app using Office 12 Interop Patrick_B 11/5/2008 7:17:02 PM I have an .NET 3.5 C# application with references to the Microsoft Excel 12.0 Object Library, the excel Interop. I deployed the application out to my office and it worked fine for everyone except one individual who got the following error: "System Update Required" "Unable to install or run the application. The application requires that assembly office Version 12.0.0.0 be installed in the Global Assembly Cache (GAC) first. Please contact your system administrator." All machines running the app have Office 2007 installed, including this one, and are running Windows XP. I had the user update their office 2007, and still got the error. I tried manually installed the PIAs following this article: http://www.microsoft.com/downloads/details.aspx?FamilyID=59daebaa-bed4-4282-a28c-b864d8bfa513&DisplayLang=en But that didn't help either. Any suggestions on what I might need to do? I've run out of ideas.

RE: Some client machines unable to install app using Office 12 Interop Michael 11/19/2008 6:30:04 AM I'm no expert, so my best suggestion is to just check "C:\Windows\assembly" just to make sure that he appropiate dll is there. Maybe even uninstall it and then reinstall via the PIA installer. Another place to check is Event Viewer under Computer Management to see if there is any more useful details or is that where you copied the error message from? As a last resort I found you can extract the dlls out of the msi installer using <http://blogs.pingpoet.com/overflow/archive/2005/11/16/14995.aspx> and copy the dll into your project and link to it directly. Then it just gets distributed along with the exe, it's what I do to get my application working office xp, 2003 & 2007.