That dll is a windows document handler and the installer should be dealing with it properly. Earlier versions of the installer did have that problem of replacing active dll files but installer 2 or 3 should have done it.  Its not an issue if the functionality hasnt changed but the fact that the installer tried means you have an earler version of that file than the program compiler used.  It may still work ok. Ideally the program should be compiled to use a local copy of the dll from its own program folder, though thats not always possible .  If its an expected or known issue it should be in the installation instructions.