IshaqSalam clarified:
yes, downloading to the client side.
do you think if it could?
if it can't how about downloading to server side with set destination in application folder?
My goal is i want to send an email by attaching an excel file from html table.
Thank you for the clarification. Is I was afraid of, the question makes no sense. ASP.NET application, as any other Web application, has not control over the client side, and the client-side script has no control over the location of the downloaded file. This is designed this way for safety reasons. Only the browse user defines where to save all files or any particular file.
Just think about it: on many platforms, such thing as disk "C:" does not exist, even as a concept. And on Microsoft platforms which has this concept, the disk "C:" may be missing, even on Windows system with one or more hard drives. Moreover, "C:\*" (more exactly and generally, the volume the OS is located) is not a legitimate location for downloaded files.
—SA