creating windows services and download file from aspx page

And now slowly ;-)

1)
You want to write a service;  OK.
2a)
You want that service to open a browser and go to a specific website / webpage. Can't be done. A service can NOT start an interactive application; see e.g. stackoverflow.com/questions/1369236/how-to-run-console-application-from-windows-service
2b)
Or you want the service to access a website. Probably OK.

Following 2b
3)
You want to download a PDF file; OK. Step 2b will be obsolete as you can do so directly.
4)
Close a tab page; do you mean web page? Anyway, not applicable.


If this is a misunderstanding of what you want to achieve, please explain clearly.