Question: My HP Chromebook is going to reach Auto Update Expiration in September. I use it only rarely, but I would like to be able to make online purchases with it.

How dangerous is it to keep using a Chromebook that’s not continually updated? Would it make sense to install some Bitdefender security software to protect the Chromebook? — J.O., St. Paul, Minn.

Answer: All Chromebooks come with built-in obsolescence: The “Auto Update Expiration” date. After that the device will cease getting software updates. There’s no upgrade you can do to avoid it.

The lifetime of a Chromebook (as measured from the device’s introduction date) has varied. Within the last five years, a Chromebook’s lifetime has increased from five years to six and a half years to — on some new models — eight years. (To find a Chromebook’s expiration date, see tinyurl.com/krbzccrn).

It is possible to keep using an expired Chromebook, although as the Web browser becomes outdated it might not work as well. And using an expired Chromebook isn’t as risky as continuing to use a PC with Windows 7 — which, like an expired Chromebook, no longer gets software updates, including security updates.

That’s because, unlike a Windows 7 PC, an outdated Chromebook has very little software that can be exploited by hackers; it typically consists of a minimalist (and well-protected) Chrome operating system and a Web browser. In addition, the number of Chromebooks in use (there are tens of millions of Chromebooks compared to about 1 billion Windows 10 PCs) keeps them from being the main target for hackers.

However, if you keep using an expired Chromebook, you should take some precautions:

• Don’t add any new “extensions” (add-on programs) to your Chrome browser. Hackers can use compromised or fake extensions to attack your Chromebook.
• Only visit websites you trust. Some websites contain malware.
• Use security software — if you can. Your Chromebook might be too old to use Bitdefender Mobile Security & Antivirus, which is an Android app. Chromebooks officially gained the ability to run Android apps in 2016, but the feature wasn’t available on all models.

Question: We’re having trouble updating Windows 10 on our Dell Inspiron 15 5000 Series PC. A pop-up window said we would no longer receive updates because our Windows 10 version (1909) is outdated. I’ve included some details about the PC. What can we do? — M.L., White Bear Lake, Minn.

Answer: The information you sent helped narrow down the likely cause of the update problem. Your 2016 PC is new enough for the update, and it has plenty of hard disk storage space for Windows 10 installation. That leaves three potential causes:

• Non-Microsoft security software that interferes with an update. You should temporarily disable or uninstall your antivirus software to see if that will allow the update to occur.
• Some software that’s needed for the update isn’t running. (To turn it on, see tinyurl.com/yrrvfx9h and scroll down to “keep all services about Windows Update running.”
• There’s a flaw in your version of Windows 10. Run a program called the “Windows Update Troubleshooter.” Go to Control Panel, choose “large icons” and click “troubleshooting.” Under “system and security,” click on “fix problems with Windows Update.”