Q: Since February, Apple's iTunes music store has been giving me a strange message: I can't download anything because I have no Internet connection. The odd thing is that I haven't had any problem connecting to other websites. When I ran a PC diagnostic program, I got error message 11222.

I've read online that other people have this problem, too. But when I talked to Apple's technical support people, they had no idea how to fix it. What should I do?

Jim Brown, Manchester, N.H.

A: Apple says it is working on your problem but doesn't have a definitive answer yet.

In an iTunes troubleshooting guide updated in May (tinyurl.com/nftgpuc), Apple offers a list of possible solutions, such as changing settings in the Apple Macintosh or Windows PC operating systems, or updating software drivers for the computer's graphics card. Apple says it is still investigating why people receive error code 11222 when trying to use iTunes. "Proxies, certificate issues, or your Internet service provider may be the cause," it says.

By proxies, Apple means "proxy servers," which are computers that act as middlemen between your home computer and the Internet. Proxy servers are sometimes used to filter Internet content before it reaches you, or to provide you with anonymity while visiting websites.

By certificate, Apple means a website's "security certificate," which verifies to a Web browser that the website is authentic.

To correct error 11222, Apple suggests changing your Internet Explorer Web browser settings. (While iTunes isn't viewed through Internet Explorer, the music service uses some of the browser's settings to communicate with your PC.) That will alter the way Internet connections are established and the way that website certificates are determined to be valid. If those changes don't work, we'll have to wait for Apple to come up with a better answer.

Two readers of last week's column (see tinyurl.com/qeqv7vn) asked why I didn't recommend an alternative home networking technology to a reader who had a problem getting a Wi-Fi signal in the garage 150 feet from her house.

That alternative is the power line. Adapters can be used to send computer data over a home's electric wires: one at the PC or network router, and the other closer to the location where the signal is needed. For an overview of power line adapters, see tinyurl.com/pqdurm7.

Because of the limitations of home wiring, I think power line adapters aren't the best solution. Those limitations include:

Slowdowns: Download speed would be slowed by using such a long home electrical wire.

Interference: Each time the data signal moved from one home circuit to another, it would pass through a circuit breaker that caused interference.

Wiring: Age and condition could affect the quality of the signal.

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.