<a href="http://www.test.com/salary.doc">下载文档</a>

------解决方案--------------------

两种方法，前面相当于客户端链接，后面是服务器处理
HTML code
<a href="aaa.doc">下载文档</a>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />

------解决方案--------------------
用客户端链接就可以了，注意路径
<a href="word.doc">word文档下载 </a>

------解决方案--------------------
protected void Button1_Click(object sender, EventArgs e)
{
   FileStream fileStream = new FileStream(Server.MapPath("abc.doc"), FileMode.Open);
   long fileSize = fileStream.Length;
   Response.ContentType = "application/octet-stream";
   Response.AddHeader("Content-Disposition", "attachment; filename=\"" + HttpUtility.UrlEncode("abc.doc", System.Text.Encoding.UTF8) + "\"");
   Response.AddHeader("Content-Length", fileSize.ToString());
   byte[] fileBuffer = new byte[fileSize];
   fileStream.Read(fileBuffer, 0, (int)fileSize);
   fileStream.Close();
   Response.BinaryWrite(fileBuffer);
   Response.End();  
}