There are two ways to do so
1. in the asp file where you have the link:
<a href="myapp.exe">click here to download</a>
when user clicks on the link, the browser will download that file and let user chooses between "Save", "Open", "Cancel".
2. <a href="pushtouser.asp">click here to download</a>
when users click on the link, pushtouser.asp will open the file, read the content, collect other information (size, name ...) then Response.BinaryWrite(content) to the browser.
The first way is the easiest way.