A digital virus that has wreaked havoc on thousands of computers every year on April 26 since 1999, failed to cause many computing problems yesterday in Beijing, experts said last night.

The CIH virus overwrites the hard disk and Flash BIOS (basic input/output system) of an infected computer, causing complete loss of data and possibly rendering a computer unbootable, experts said.

"The emergency alerts issued by anti-virus vendors and the media days before the virus' triggering date seemed to have worked," said Liu Xu, a senior software engineer.

"We only repaired 52 computers today which were paralyzed by the virus, while on April 26 last year, Beijing alone saw the infection affect 6,000 computers."

However, the damage caused by another virus, Worm.Klez, a variant of another notorious program transmitted by emails, by far outweighed those inflicted by CIH yesterday, he said.

Liu's Beijing Rising Computer Sci-Tech Co received 4,100 phone calls nationwide for anti-virus help yesterday.

(China Daily April 27, 2002)