This is a free library and works very easily : OpenHtmlToPdf
string timeStampForPdfName = DateTime.Now.ToString("yyMMddHHmmssff");
string serverPath = System.Web.Hosting.HostingEnvironment.MapPath("~/FolderName");
string pdfSavePath = Path.Combine(@serverPath, "FileName" + timeStampForPdfName + ".FileExtension");
//OpenHtmlToPdf Library used for Performing PDF Conversion
var pdf = Pdf.From(HTML_String).Content();
//FOr writing to file from a ByteArray
File.WriteAllBytes(pdfSavePath, pdf.ToArray()); // Requires System.Linq