Hello Pf course I'll assume you are doing this using COM interop. Actually the dll that's in your application's folder is something like a router. All it does is to call whatever version of Excel that's present on the user's computer to do the job. So it all depends on the version that's installed on the runtime machine. To solve the issue you have two options: 1- In the reference list of your project try to set ht eIsolated property of the interop library to true -this tries to prevent version conflect, but sometimes doesn't work- 2- Make Excel 2000 as a "minimum requirement" for your application, so that users would know that have to have it on their machines. 3- Remove whatever features you are using that requires Excel 2000 to be on the machine -This is NOT guranteed to solve the issue. Actually it's likely NOT to work!- 4- You can also try 3rd party libraries which doesn't require Excel to be installed at all. And for the solution suggested by Ista,it would work, but it's hard to implement specially with large applications such as Excel, as each dll may call other functions in other dlls. Regards:rose:
