>Is there a way in .NET to zip a file? I have a XML file that I need to send to the user. But, as it is in XML, it is shown in browser. If I zip the file, it will be send on top of the current page so the user can then decide where to save the file.

Yes my coders use www.zlib.org zipping/unzipping source code to create our own component, which zip data on server and unzip them in browser. But unzipping require HTTP object, which is blocked by IE if it is on high security level