Hi everyone, We have an application that is built with Excel as the front end using the Office object model. We were using a C++ shim to load it as a COM add in for Excel 2003, but I've updated it to use the latest VSTO for Excel 2007. I've also been using VS 2010 for the latest version. The problem is that everything works great on my dev machine in debugger mode as well as just launching Excel 2007, but I cannot get it to run on any other machine (my current target machine is Win7, development is XP). I've created a ClickOnce deployment of the Addin, and I can see it in the list of COM Addins, but when I check on it to load it nothing happens. I re-open the Addins manager and it is un-checked. I've also tried setting in in the registry, but as soon as I run it, it sets the registry back to do not load. I've tried everything I can think of and searched all over the web but no dice. Any help would be appreciated!