"How could I have caught a computer virus? All I do on my computer is write papers and check my e-mail!"

No doubt many Harvard students felt this way recently, as they found their IBM-compatible PCs suddenly unable to run Windows and other programs. Most students couldn't think of anything that could have infected their computers.

But the source of their infection was the Harvard network itself. HUSC1--the Novell server, which provides the familiar "blue screen menu" to Windows and DOS users--was infected with a virus known as little_red.a.

Every PC user who logged into HUSC1 from their dorm rooms to use the network on the night of December 18 soon found their computers paralyzed by the virus.

Of all the viruses out there that could have struck, little_red.a is one of the least destructive. It doesn't affect data files, like Matlab assignments or thesis chapters, and infected computers could be fixed in minutes with HASCS's anti-virus diskettes.

But while Harvard users dodged the bullet with little_red.a, the crisis raises an important point: there are things everyone can do to protect their computers and files from virus attacks.

1. Use anti-virus software. Perhaps the easiest thing you can do is install software that can detect and intercept viruses before they can harm your system.

Symantec produces two of the best anti-virus programs on the market. Symantec Anti-Virus for Macintosh (SAM) and Norton Anti-Virus 3.0 for Windows are among the top programs for those two operating systems.

DOS users can access the FPROT program via the Harvard network; it appears as an option on the main menu and is free of charge to Harvard users. One of the few anti-virus programs available for Windows 95 is McAfee's VirusScan. It installs easily, automatically scans and disinfects diskettes and files, and can be controlled from the taskbar tray.

2. Update your software. Just because you've installed anti-virus software, you're not out of the woods. On an average day, 3 new viruses are created; no matter how good your software is, it can't stop a virus that it doesn't know about.

In fact, the little_red.a infection of HUSC1 happened because the system administrators were running outdated virus protection software. Even computer professionals can forget to update their files.

Fortunately, many of the programs make updating easy. Symantec's SAM can automatically contact the company's computer system via modern to update its database of virus information. Other programs, like McAfee's VirusScan, have monthly updates available via the World Wide Web.

Make sure to update your anti-virus software every three to four months.

3. Be careful what you put on your computer. Most people wash their hands before they eat; you never know what you've picked up. Similarly, remember that when you get files via floppy disks or the Internet, you're trusting the health of your computer to other individuals, who may not have disinfected their files.

Some Web browsers, like Microsoft's Internet Explorer, warn you of this when you try to download files. Most software on the Internet is virus-free, but it doesn't hurt to check them with your favorite virus checker before running a downloaded program.

You should also be very careful when using other people's floppy disks. Viruses often spread via disks, going from system to system. And never install other peoples' copies of software on your computer. Besides being illegal, "pirated" software is more likely to have viruses, since the disks are often passed among countless computers.

4. Don't panic over hoaxes. Remember that viruses can only be sent through software, and that you can't get viruses just by reading e-mail. If you get a hoax e-mail, let the sender know that they're passing on false rumors--or at the very least, don't pass the rumor on!

Kevin S. Davis '98 is the Currier House User Assistant as well as HASCS's Networking Advanced Support technician. His e-mail address is ksdavis@fas.harvard.edu.