ASP.Net HttpPostedFile save Error: Access to the path is denied

I want to upload multiple images to folder on button click. I get error like acess to path is denied in uploadedFile.SaveAs method.

Access to the path D:\Codes\Kanpur Applications\... is denied

I have enabled all the permission to the folder still i get acess denied error.

string strPath = Server.MapPath("~/Source images/" + HiddenField2.Value);
if (FileUpload4.HasFiles)
{
    foreach (HttpPostedFile uploadedFile in FileUpload4.PostedFiles)
    {
         uploadedFile.SaveAs(strPath);
    }
}

Please help