"Your data was delicious." That's the computer message that greeted Anthony Ferdaise and his business partner when they returned from a lunch break one day last October. To his horror, Ferdaise discovered that every file on their personal computer's hard drive had been erased, apparent casualties of a computer virus.

Ferdaise and his partner, who are starting a San Diego- based fitness magazine, used data-recovery software in a vain attempt to recover some of the lost files. Unfortunately, they hadn't backed up their hard disk for more than two months. Ferdaise estimates that the time it took to reinstall the partners' software, re-create their data, and once again scan in photos set the magazine's launch back by six months.

Ferdaise says he has learned two valuable -- if painful -- lessons from his experience: check for viruses regularly, and back up religiously. He has purchased a tape backup system, which performs automatic, incremental backups in the middle of the night. Ferdaise says he also scans his system for viruses about once a week. To those who think viruses won't strike them, Ferdaise cautions, "I said the same thing -- and it happened to me."

For a copy of How to Avoid Computer Viruses, a 19-page, three-by-six-inch pamphlet published by the National Computer Security Association and 3M, send $2 to the NCSA, 10 S. Courthouse Ave., Carlisle PA 17013. Write "virus brochure" on the outside of the envelope.

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