Revelations that security flaws in chips powering PCs, laptops, servers, phones, and other devices have gone unnoticed for years have whipped bug fixers and security experts into a frenzy this week.

The flaws, which researchers have code-named Meltdown and Spectre, relate to how a CPU handles tasks that it thinks your PC will need to perform in the future, known as speculative execution. According to Google’s Project Zero security team, in a worst case scenario the flaws could be exploited to reap sensitive information from these commands-in-waiting.

The good news is that some patches have already rolled out, but the bad news is that because so many companies are involved—from chip manufacturers to PC makers to operating system companies—figuring out if your computer is fully protected isn’t straightforward. For now, there are a few separate courses of action to follow to fortify your device, depending on which operating system you have. Then there’s the additional step of updating web browsers and other program, which every computer user should do regardless of OS.

For Windows

Microsoft released a cumulative security update on Wednesday that offers software-level protection against speculative execution, which should roll out automatically to systems running Windows 10. To be sure your computer is up to date, open the Start menu, click the gear icon to open Settings, and click on Windows Update.

Microsoft notes that the mitigations may slow down your computer. “For most consumer devices, the impact may not be noticeable, however, the specific impact varies by hardware generation and implementation…