Network Solutions Inc., also known as InterNIC, administers Internet domains such as .com, .gov and .net. The company's database failed during a routine five-days-a-week computer update of domain names, resulting in a corrupted update file for .com and .net being sent to seven of the Net's nine root servers. A company spokeswoman blamed human error for the problem. She said that when database files were corrupted at 2:30 a.m. EDT, NSI's quality assurance system raised an alarm, but the system administrator on duty forwarded the files nonetheless. "We will take all necessary action with this employee," who was responsible for checking the integrity of the files, she said. The corrupted files left out the majority of the registrations in the .com and .net domains. The files were passed on to computers all over the world, effectively deleting all those sites. Although the sites were still there, they no longer existed as far as the computers were concerned. System administrators who didn't update their systems were not affected, because old records can still be used. And those who updated could fix the problem if they had a copy of the old file in their cache. InterNIC found the problem quickly and sent the proper update file by 6:30 a.m., the spokeswoman said. Still, there was a ripple effect, as the corrupted file spread over various servers on the Net. Posts on Usenet indicate that many Web administrators found and fixed the problem on their own servers before it could affect users. But the corrupt file caused headaches for users worldwide who were stuck wondering where the Net went. "People aren't necessarily getting the right source for the .com address, so it looks like the server is down when in fact it is a [Domain Naming System] error," said Adam Hersh, senior engineer at Apex Global Internet Services Inc., in Detroit. An engineer at an Internet service provider who requested anonymity said he has been flooded with calls from users suddenly faced with an empty Internet. "Things just aren't resolving correctly if they resolve at all," he said. The spokeswoman said that this is the first time such an event has happened in the four and a half years NSI has performed the function, and the company would be revisiting its update methods.