.sit files open as Word during install in OSX
 

I apologize for posting this question but I've been all over the various forums and have seen the question posed previously but not answered.

I know I need to install stuffit expander before I try to install and run limewire. I also know I can NOT launch either of these .sit files from my desktop. I've moved them into other folders under "applications".

When I access the folder and click on the .sit file, Word launches but NOTHING happens. I changed the file extension to .zip and I get the same result. Nothing.

Can any of you pros out there lend a hand in helping a girl get to great music? Thanks!!!!