The company could not be reached for comment this morning.
The outage follows others reported by large companies, including one at Amazon.com last week and a prolonged slowdown for Toys "R" Us two weeks ago. The timing is inopportune, coming during Thanksgiving week, marking the traditional start of the holiday shopping season.
A Dell representative confirmed the problem and said the PC maker's technical force was working to fix it. He said the outage was limited only to the Round Rock, Texas-based firm's home page.
Responding to CNET News.com, Dell issued this statement:
"We are aware that www.dell.com is not accessible to many Internet users. The problem, which resulted from a routine networking procedure, is in the interface between the Dell network and Internet service providers. The issue has nothing to do with the dell.com site itself, the recent redesign/relaunch of dell.com or the hardware or software on which it runs.
"This matter began to appear early this morning but became notable around midday. We believe it is limited to the U.S.
"We are working to resolve the issue as quickly as possible, and expect to have a fix in place this afternoon that will immediately limit the problem, and eliminate it completely over 24 hours."
Potential Dell customers told CNET News.com that the site suffered a similar problem last weekend. "The Web site worked one minute, but didn't work the next," one wrote in an email message.
A spokesman said he was not aware of any problems on the weekend.
Consumers are expected to buy an estimated $5 billion in items, including PCs, this holiday season, according to analysts.
Next week, Dell is expected to launch a lower-cost PC dubbed WebPC.
Dell redesigned its site during the weekend of November 7, John Zoglin, director of online technology at Dell, said previously. The redesign mostly occurred to make the site more intuitive for users and to clear up some technical issues, he said.
The company kicked off the Web site in 1996 but let it grow in a relatively ad-hoc fashion, he said. As a result, the site was comprehensive but not organized as efficiently as possible. Changes to the site were also not centrally managed as efficiently as they could have been, Zoglin said.
Online sales constitute a huge part of Dell's sales. Chief executive Michael Dell recently said that 43 percent of the company's business is transacted via the Web and nearly half of its consumer business comes from the site.
News.com's Michael Kanellos contributed to this report.