I don't think there's a way to override this though - you can change the Mime type settings of the format though I believe. Find a file with the .csv extension and and right click on properties. There should be an option page somewhere that allows you to select what app opens it and whether there is prompting or not.
Note that it 'll also help if you provide an explicit Content Type type in your output of the file.
+++ Rick ---
It is indeed a security issue. If I navigate to a webpage first and then refresh that page and redirect to the csv file, Vista puts up a bar at the top of the browser saying "download has been blocked, click here etc." and at least you get to click there and accept the download. But I could not find a setting in Internet Options Security settings to avoid this hassle.
What a pain!
Reg
| Rick Strahl West Wind Technologies Where do you want to surf today? | Reader Version: 5.0 |