i am looking for a activex control or a tutorial that will help me do the following

has to run in a web browser that if the user runs, it will tell them weather a certain file is on their computer or not
if not then they should have it before they can use the application

basically i wanna make 2 installations of my app
one with the run-time files, and the other, just .exe
but i want to make sure they user has the run-time files
thanks