Now that the OS and computer has been dragged out, here are a couple of more questions that having the answer to would be advantageous to those trying to answer your question.
1. What are you trying to download? (The exact name of the file}
2. Where are you trying to download it from? (The exact URL of the site)
3. Have you been able to download any other apps from the same site?
4. Have you been able to download any other apps from different sites?
Download application store program stops during intial start up?