When the computer screen of Andrew G. Eil '02 froze late last Sunday night, he figured the troublesome PC was just acting up the way it always does.

So he tried to reboot it.

Then he tried again.

And again.

The next day, Eil Visited the computer help desk in the Science Center basement and learned that his hard drive had been irreparably damaged.

And his was not the only one.

Eil's computer, like many others on the Harvard campus, was struck by the Chernobyl virus.

"They [the Science Center User Assistants] told me my hard drive was erased and that they couldn't see me until next Sunday," Eil said. "That doesn't help much."

The virus, which was triggered on April 26, disabled several hundreds of thousands, of computers all over the world. as computer experts had warned it would. At Harvard, it hit students with end-of-the-year projects looming especially hard.

Only about 2,000 computers in the U.S. were hit, probably because use of virus protection software is more prevalent here than in other parts of the world, according to Bill Pollak, a spokesperson for Carnegie Mellon's Computer Emergency Response Team (CERT). He said computer users could have downloaded a file with the virus in it unknowingly at any point in the last few months.

"It lies dormant in the computer system and then delivers its payload on the 26th of April," he said.

Pollak said that most reports of the virus came from home computer users or college students. He speculated that large corporations might have escaped major damage because they tend to use effective anti-virus programs.

This is the first outbreak of this devastating computer virus. While similar viruses can be triggered every month, Chernobyl was set for a particular day, this April 26, the thirteenth anniversary of the Chernobyl nuclear accident.

Not all students were struck. unaware--this week's issue of the Yard Bulletin warned first-year of the virus and told them to consult the Science Center help desk if they encountered problems.

Kunj Majmudar '99 said he heard about the virus last Thursday and backed up several of his files, just in case. Unfortunately, he was not worried enough to back up all of them.