<p><a href="https://www.lifewire.com/windows-8-2626235" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">Windows 8</a>, as well as most <a href="https://www.lifewire.com/operating-systems-2625912" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">operating systems</a> and other software, require the entry of unique product keys, sometimes called <a href="https://www.lifewire.com/serial-number-2626008" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="3">serial numbers</a>, during installation. Halfway through reinstalling Windows 8, you must have your <a href="https://www.lifewire.com/what-is-a-product-key-2625952" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="4">product key</a> to continue the installation.</p><h3>Where the Windows 8 Product Key Is Located</h3><p>Usually, your Windows 8 product key will be with the email you received after buying Windows 8 for download, or if you purchased it in a box with a disc, with the packaging. If Windows 8 came preinstalled on your computer, your product key should be on a sticker on your computer or with your documentation. It should look a lot like the image you see here.</p><p>Fortunately, if you can&#39;t find documentation of your Windows 8 product key, you may be able to extract it from the <a href="https://www.lifewire.com/windows-registry-2625992" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="5">Windows Registry</a> using a program called a <em>product key finder</em>. It&#39;s a quick process that takes less than 15 minutes.</p><p><strong>Important:</strong> A product key finder program will only find your valid Windows 8 key if Windows 8 is installed and working, and if you&#39;ve manually entered the Windows 8 product key in some previous installation. See my <a href="https://www.lifewire.com/windows-product-keys-faq-2624937" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="6">Windows Product Keys FAQ</a> and <a href="https://www.lifewire.com/key-finder-programs-faq-2625113" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="7">Key Finder Programs FAQ</a> pages for more help.</p><h3>How to Find Your Windows 8 or 8.1 Product Key</h3><p><strong>Note:</strong> You can find your Windows 8 or <a href="https://www.lifewire.com/windows-8-1-2626251" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="8">Windows 8.1</a> product key this way, no matter what edition of Windows 8 you&#39;re using.</p><ol><li><a href="https://www.lifewire.com/belarc-advisor-review-2625784" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="9">Download Belarc Advisor</a>, a free PC audit program with full Windows 8 support that also functions as a key finder tool. Unfortunately, manually locating the Windows 8 product key in the registry isn&#39;t possible so you&#39;ll need to use a program like this.<br/><br/>See my <a href="https://www.lifewire.com/free-product-key-finder-programs-2625119" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="10">List of Free Key Finder Programs</a> for more tools like Belarc Advisor, but try it first since I&#39;ve confirmed that it correctly finds Windows 8 product keys.<br/><br/><strong>Note:</strong> Any product key finder that advertises support for Windows 8 will work for either edition: <em>Windows 8</em> or <em>Windows 8 Pro</em>, as well as either edition of <em>Windows 8.1</em>.<br/> </li><li>Install Belarc Advisor, following the instructions given during the installation.<br/><br/><strong>Note:</strong> If you choose a different keyfinder, please know that some are supported by optional add-on programs so be sure to uncheck those options during the program&#39;s installation if you don&#39;t want them. A few of them require no installation at all.<br/> </li><li>Run Belarc Advisor (the initial analysis may take a little while) and note the Windows 8 product key displayed in the <em>Software Licenses</em> section.<br/><br/>The Windows 8 product key is a series of 25 letters and numbers and should look like this: <strong>xxxxx-xxxxx-xxxxx-xxxxx-xxxxx</strong>.<br/> </li><li>Write down the Windows 8 key exactly as shown for use when <a href="https://www.lifewire.com/how-to-clean-install-windows-8-or-8-1-2626254" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="11">reinstalling Windows 8</a>.<br/><br/><strong>Important:</strong> Make sure each and every letter and number is written exactly as shown. If even one digit isn&#39;t transcribed correctly, the key won&#39;t work to reinstall Windows 8.</li></ol><h3>More Windows 8 Product Key Ideas</h3><p>If you need to install Windows 8 but wasn&#39;t successful finding your Windows 8 product key with a product key finder program, you have two more choices:<br/><br/>You can <a href="https://www.lifewire.com/how-to-request-a-new-windows-product-key-2624936" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="12">request a replacement product key</a> or you can <a href="https://www.microsoftstore.com/store/msusa/en_US/cat/Windows/categoryID.62684800?tduid&#61;%28df9556b3dcc63111a51acc05582ba116%29%28256380%29%282459594%29%28xIKL5.ppAuE-wh9PDGWhfVNPWC5iLb1hYg%29%28%29" data-component="link" data-source="inlineLink" data-type="externalLink" data-ordinal="13" rel="nofollow">purchase a new copy of Windows 8.1 from Microsoft</a>, or another retailer like <a href="https://www.amazon.com/s/ref&#61;nb_sb_noss_2?url&#61;search-alias%3Daps&amp;field-keywords&#61;windows&#43;8" data-component="amazon" data-source="affiliate" data-type="externalLink" data-ordinal="14" rel="nofollow">Amazon</a>, which will, of course, come with a new and valid product key.<br/><br/>Requesting a replacement Windows 8 product key is going to be much more cost effective than buying an entirely new copy of Windows 8, but you may have to do that if the replacement doesn&#39;t work out.</p><p>If you need more help, see my <a href="https://www.lifewire.com/get-more-help-2625173" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="15">Get More Help</a> page for information about contacting me on social networks or via email, posting on tech support forums, and more. Be sure to let me know what you&#39;ve already tried so we can work from there.</p>