Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly ‘Microsoft.Office.Interop.Excel, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c’ or one of its dependencies. The system cannot find the file specified.

Once again, I took to the web, looking for the answer.  I found links and articles, read them, tried them and still didn’t work.  Last night, I was talking to a ex co-worker at Microsoft who is a seasoned C# developer and I brought up the question.  He, of course, was in bed and I was pretty much talking to myself via MSN Live Messenger.

But this morning he responded to my question:

RD says (8:10 AM): look at your references in your project, and make sure all of them are set to copy local. Then when you deploy, deploy all the dlls with your exe.

you can find this by expanding ‘References’ –> click on the reference and go to its property.  There look for, Copy Local.  By default, this is set to False.  Change it to True.  Setting the references to True will tell Visual Studio to extract the DLL from where-ever the hell it is stored (actually, you can tell where it is stored) to the bin\debug or bin\release folder when the project is compiled.  All you have to do afterward is copy the freshly minted .exec, .dlls, and .config (if one is used) to any Windows machine and it will work.

Thanks RD.