Windows 7 Starter Edition Ita Torrent

I have HP Mini 210 with Windows 7 Starter pre installed in it. I had some truoble there and I lost my windows, don't have installer. I have serial key. When I tried to download new windows 7 starter from Microsoft official website verification of my serial key said:

"The product key you entered appears to be for software that was pre-installed on a device. Please contact the device manufacturer for software recovery options."So here I am, contacting my manufacturer for software recovery options. What are they? What do I have to do to get my windows 7 starter again?

To deal with this situation, the software giant comes up with a solution named as Convenience Rollup Package for Windows 7 SP1, the latest service pack for windows 7, and people also called it Windows 7 SP 2 2b1af7f3a8