QMy McAfee firewall periodically detects a port attack that I can trace to a company called UUNet. I have tried to call this company on many occasions and always get a busy signal. What can I do to stop this persistent attempt to get into my computer?

ADon't freak out: Any computer on the Internet will be subject to this sort of break-in attempt, but as long as these attempts don't succeed, there's nothing to worry about. You can make sure they fail by keeping a firewall active and installing all the security updates available for your system.

UUNet most likely is not the culprit. This MCI subsidiary carries a big chunk of the Internet's traffic, and these attacks often use it as camouflage to conceal their origin.

If, however, your firewall reports port attacks coming from your machine, you definitely should freak out. In that case, your PC has probably been taken over by a virus or worm and is being used to launch attacks against other computers.

I have converted from 35mm film to digital and am concerned about storing my files on CDs. During a recent photography trip, my guide warned me that most recordable CDs will self-destruct in about two years. Is that true?

No. Recordable CDs don't self-destruct in two years or anything close to it. According to disc vendors' estimates, that lifespan should be anywhere from 70 to 100 years, if a CD-R is kept out of direct sunlight and stored at room temperature.

Rewriteable CDs may not last as long; TDK, for example, estimates a lifespan of "only" 30 years for its CD-RWs, versus a century for its CD-Rs.

For more details about the proper care of CDs and DVDs, have a look at the report issued by the National Institute of Standards and Technology last October: www.clir.org/pubs/reports/pub121/contents.html.

-- Rob Pegoraro

Rob Pegoraro attempts to untangle computing conundrums and errant electronics each week. Send questions to The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or rob@twp.com.