Alexander: Here's how antivirus software works

I've been getting a lot of questions about antivirus software for Windows. Because antivirus software is essential for safety, it's important to know how it works.

Here are some answers:

Q: Once Windows 7 is no longer supported by Microsoft, will antivirus software be enough to protect our PCs?

Dick Bielke and Lucy Winn, Edina.

A: No. Starting in January, 2020, Windows 7 will no longer receive security updates from Microsoft.

If new Windows 7 security flaws are discovered after that, no antivirus program will be enough to protect your PCs. You will need to upgrade to a newer operating system to be safe.

Q: Does Microsoft's free antivirus software conflict with many other antivirus programs?

A: All antivirus programs conflict with each other, which is why you should never run two of them at the same time.

Fortunately, if you have Windows 8.1 or Windows 10, the built-in Windows Defender antivirus software will automatically turn off if you install another antivirus program.

If you use Windows 7, uninstall whatever antivirus program you are currently using before installing a new one (Defender isn't a full-fledged antivirus program in Windows 7.)

Q: For several years, I've been using the Windows 10 Defender antivirus program as well as Malwarebytes Premium. But now my PC seems to be slowing down; does that mean these two programs conflict?

Joyce Cote, Manchester, N.H.

In the Windows 10 search box, search for "virus," then click on "virus and threat protection," then click on "virus and threat protection settings."

If the switch icon below "real-time protection" is on, Windows Defender is still running. Move the switch to off. If it doesn't stay off, reinstall Malwarebytes Premium and check Defender again.

And on another topic:

Q: The File Explorer program constantly opens by itself on my Windows 10 PC. In addition, I find the type size in Windows 10 Mail to be too small. What can I do?

Harry Green, Houma, La.

You can't change the default type size in Windows 10 Mail, which is set to the Calibri font and type size 11. However, you can manually change the font and type size each time you compose an e-mail or reply to one (see tinyurl.com/yclvbrdx).