One of the three ways to tell Network Solutions to change a domain name is by e-mail, Kurtz says. In AOL's case, someone forged an e-mail message from an AOL site administrator. Network Solutions mistakenly changed the DNS information, so an AOL site pointed to somewhere else, he says.
It's unclear whether Microsoft's domain names were hijacked, the DNS was hacked, a simple domain name system error occurred, or some other problem caused the snafu.
But something caused the Web sites of the world's largest software company to go AWOL for a very long time Wednesday.
(Ashlee Vance of the IDG News Service contributed to this report.)