data downloader of stock from yahoo

We want a downloader which will:- 1. download historical data of any stock given in yahoo finance site. 2. convert it into meta stock data format. 3. update the corresponding data file in the respective folder by appending the file. Similar software: HQuote([login to view URL]). we are uploading the demo version of it, in zip format, for ready referrence. We also want a kind of registration mechanisam for the downloader that will generate the registration code depending on the harddisk number of the pc/laptop so that pirecy could be averted.