how use download all type file in asp.net?

hi
how use download all type file in asp.net?

example :
<a temp_href="/Upload/C#_3.rtf" href="/Upload/C#_3.rtf">download</a>
HTTP Error 404.0 - Not Found

<a temp_href="/Upload/Attachments_201361.zip" href="/Upload/Attachments_201361.zip">download</a>
True
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