Q My HP notebook PC with Windows Vista has been running very slowly, and I'm wondering if I may have installed some type of malware. I checked Windows Help and Support, and it suggested I use the Windows Defender software that's included with Vista.

I got an error message when I tried to run it, and now I can't uninstall it because it's not in my list of programs. I can't download it again because the PC says I already have it.

I tried running Malwarebytes' Anti-Malware, Stinger, Ad-Aware, Spybot, HouseCall and AVG, but while they all found and repaired some problems, the PC is still slow.

Because Windows System Restore wasn't turned on, I can't use it to return my PC settings to a time before the PC slowdown occurred.

Any suggestions?

MIKE PRINSKE, EAGAN

A You're running too many programs that do the same thing, and they're slowing down your PC.

HouseCall, AVG, some versions of Ad-Aware and, to a lesser extent, Stinger are antivirus programs. Pick one (not Stinger) and uninstall the others.

Windows Defender is a spyware removal program that scans automatically, and thus uses up computing power. You don't want it to run. If it does, read how to turn it off at tinyurl.com/66ffqz.

Spybot and Malwarebytes scan for malicious software, but don't run continuously, so keep both.

Q We would like to change our e-mail accounts from the Outlook Express program on Time Warner's Road Runner Internet service to Google's Gmail. How can we transfer our extensive address books to new accounts without having to retype each address?

KATHY HART, SOUTHPORT, N.C.

A To learn how to import Outlook Express address books to Gmail without retyping anything, go to tinyurl.com/yjwxxnu.

Q I own a two-year-old HP Pavilion PC that has no sound. I paid $50 to have it "tweaked" at a local computer shop, but I still don't have any sound. The computer shop said the sound worked when they tested it. What's wrong? Is my monitor at fault?

LONI COLEMAN, APPLE VALLEY

A The problem is in the PC, not the monitor. Several HP PC owners have had sound problems.

If the headphone jack works but the computer speakers don't, HP offers a software solution. See tinyurl.com/3tx665.

Some HP laptop owners have found that their speakers don't work because of a bad electrical contact inside. See a YouTube video at tinyurl.com/c8kqrm. If that's it, try a repair shop.

E-mail tech questions to steve.j.alexander @gmail.com, or write to Tech Q&A, 425 Portland Av., Minneapolis, MN 55488-0002. Include name, city and telephone number.