Patching up your PC against "Meltdown" and "Spectre" will involve updating Windows 10.
It's possible that Windows' update feature already automatically downloaded and installed the patch, but you may need to restart your computer to finalize the patch.
Either way, you'd do well to check whether any updates are available for your PC. In Windows 10, click the search bar on the bottom left > type "Update" > click "Check for Updates > click "Check for updates" again the the Windows Update menu.
If Windows is showing that it's already downloaded the update, follow the prompts on the screen. It could tell you to install or restart your computer.