As an experiment, Steve Knopper bought a Dell computer and left it unprotected — and clicked on every dubious link he could find. He kept a diary. Here are the last few days.

Day 10: I download Kazaa, search for .xxx, .gif, .rar, .pif, and .exe files, and open everything. My desktop is soon stuffed with pornography, MP3s in Arabic, and pirated copies of Tomb Raider. Within minutes, Explorer has a grand mal seizure – 95 pop-ups and innumerable error messages. Hah!

Day 11: Incredibly, the Dell boots up. I’ve gotten some strange attachments that Yahoo, Outlook, and Eudora won’t let me open. I try copying some from my regular computer to the Dell using an external drive. Nothing.

Day 12: Upon firing up the computer, I get six Internet Explorer pop-ups, one WhenUWin Sweepstakes, and one “The Best Offers.” McAfee VirusScan says I have 25 potentially unwanted files, including W32/Netsky.q@MM!zip and two other viruses. SaferScan finds 1,002 porn files on my hard drive, and my Yahoo Mail inbox has 200 brand-new messages with subject lines like “Tired of dating games?”

Day 18: I take the Dell to Best Buy’s Geek Squad and tell a technician that I’m having a bit of trouble with it. Less than four hours later I get a call back from Carla. She declares it a total loss and advises wiping the hard drive and restoring it with system disks. “The tech ran a couple of virus scans,” she says. “One kept beeping so much that he had to just turn it off.” Ah, that’s the stuff.

It was a Windows machine, you understand.