Windows 10 is arguably the best version of Windows ever, but that doesn’t mean that it doesn’t slow down over time. A Windows 10 install or any Windows install for that matter, begins to slow down over time due to number of reasons. The best way to overcome the issue is to reinstall the operating system. Automatically activate Windows 10 after the reinstall Many users who upgraded to Windows 10 from Windows 7 or Windows 8.1 using the free upgrade offer often ask how to reinstall Windows 10 install without losing the activation license or how to activate Windows 10 again after the reinstall. Soon after the release of Windows 10, back in 2015, Microsoft made it clear that one can reinstall Windows 10 and activate Windows 10 after the reinstall without any hassle if you are reinstalling Windows 10 on the same PC without making major hardware changes. Link Windows 10 license to Microsoft account If you are signing into Windows 10 using a Microsoft account (version 1607 or later), Windows 10 automatically links your Windows 10 license to Microsoft account. Linking your Windows 10 activation license to your Microsoft account makes it easier for Microsoft and its servers to quickly activate your copy of Windows 10 when you perform a reinstall or make a clean install. In fact, there is even an activation troubleshooter which you can use to activate Windows 10 if your copy of Windows 10 is not automatically activated after making changes your PC’s hardware. Users who are using a local user account can also reinstall Windows 10 without losing activation license. There is no tool around to backup Windows 10 activation license. In fact, you don’t need to backup your license if you are running an activated copy of Windows 10. Activating after reinstalling Windows 10 According to this page of Microsoft, you can reinstall the same edition of Windows 10 on the same PC (where you currently have an activated copy of Windows 10) without requiring to enter a product key. While reinstalling Windows 10, if you see a prompt asking to enter the product key, simply click the Skip option. Windows 10 will automatically activate once you connect your PC to online after completing the installation. Before proceeding to reinstall Windows 10, we advise you to navigate to Settings > Update & security > Activation to check the activation status of Windows 10. Here, you will see “Windows is activated with a digital license linked to your Microsoft account” message if your copy of Windows 10 is activated and is linked to your Microsoft account (automatically happens if you are using a Microsoft account to sign in to Windows 10). If you are using a local account, you will see “Windows is activated with a digital license” message. If you still have doubts, please chat with Microsoft support using the built-in support app or chat with Microsoft support agent online. In short, you can reinstall Windows 10 without losing the activation license. For more details about Windows 10 activation, please visit the official Windows 10 activation page.