打开ProduKey网站。 向下滚动网站，点击下载ProduKey（Zip文件）。 打开ProduKey文件夹。 点击解压缩选项卡。 点击全部解压缩。 点击解压缩按钮。 双击ProduKey，打开程序。

Given the above summary, write a detailed text in English for it.
Go to http://www.nirsoft.net/utils/product_cd_key_viewer.html on a working computer. It's near the bottom of the page. Doing so will prompt the ProduKey setup folder to download onto your computer. Double-click the ProduKey ZIP folder in your computer's default downloads folder (e.g., the desktop). It's at the top of the window. A toolbar will appear below Extract. This option is on the far-right side of the toolbar. Clicking it prompts a window to pop up. It's at the bottom of the window. Doing so will decompress the ProduKey folder and open it for you. It resembles a key. The ProduKey window will open; you should see your computer's 25-character product key to the right of the hard drive's name. You can take a screenshot of the key or write it down to make sure you have access to it later.