Initially create u r UI by using the following code:
<asp:FileUpload ID="FileUpload2" runat="server" /><br />
<asp:Button ID="Button2" runat="server" Text="Upload" onclick="Button2_Click"/>
then use this c# code to save file:
protected void Button2_Click(object sender, EventArgs e)
{
FileUpload2.SaveAs(Server.MapPath("~/Uploads"));
}
Futher reading you can go through the below link:
http://msdn.microsoft.com/en-us/library/aa479405.aspx[
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