Q: I upgraded from Windows 7 to Windows 10. Does the Windows 10 built-in security software, Windows Defender, provide enough protection against computer viruses, spyware and other malicious software? Will the Kaspersky Internet Security, which I had on my PC for Windows 7, conflict with Windows Defender?

Bruce Perkins, Woodbury

A: So far, it appears that the built-in Windows Defender does provide good security for the average Windows 10 user. In tests, Windows Defender nearly matched commercial security software in stopping malicious attacks. While your Kaspersky software did somewhat better on the tests than Windows Defender, computer security professionals disagree on whether the difference was significant (see tinyurl.com/q6hjovm). In addition, Windows Defender doesn't conflict with other security programs; it turns itself off if you use other software.

Q: I upgraded from Windows 7 to Windows 10 on my 5-year-old Dell Inspiron 1545 laptop. Since then, my screen saver won't stay on. The PC abruptly reverts back to the Windows desktop, even though I didn't do anything. What's wrong?

I also have an unrelated problem that predates my Windows 10 upgrade: My Web browsing slows down when my browser says I have a "long running script." What can I do about this?

Elizabeth Sisselman, Jacksonville Beach, Fla.

A: There have been other complaints that the Windows 10 screen saver function doesn't work properly, and so far there's no definitive solution. But in your case, the cause might be that Dell says your laptop model isn't suitable for Windows 10. (It's absent from Dell's list of Windows 10-ready PC models at tinyurl.com/odhxc4j). As a result, Dell doesn't provide Windows 10 software drivers for your PC. The drivers allow Windows to control your PC and its accessories, and without them your computer may not run well.

To deal with "long running script" error messages, see my June column at tinyurl.com/ne3sgy4.

Q: We recently purchased a new Windows 10 PC. It recognized our older printer, a Hewlett-Packard F380, but when we print we get only a test page. What can we do?

Diane Erwin, Winter Haven, Fla.

A: Your 9-year-old printer probably requires a new software driver to work with Windows 10. To find a new driver, download HP's "printer install wizard" at tinyurl.com/ow98mo2. It will determine whether your printer will work with Windows 10, and will recommend a software driver if one is available.

Editor's note: If you caught that Steve focused on Windows 10 questions this week, it was his subtle way of marking the 10th anniversary of his Q&A column. Happy anniversary to Steve — and keep sending him questions.

E-mail tech questions to steve.j.alexander@gmail.com or write to Tech Q&A, 650 3rd Av. S., Suite 1300, ­Minneapolis, MN 55488. Include name, city and telephone number.