Hi, Shot this is Tyler. Can you try inserting the LabVIEW 8.5 CD into your drive when you build the application and then instruct LV to look in your CD drive when it prompts you to be pointed to the distribution. I believe that the CD might contain files that you did not install on your computer, and LV needs to have access to those files to build your particular application. Let me know if that works out for you or not.