Microsoft acknowledged the problem.
"This morning we identified an issue which began causing a portion of our customers to experience logon and connectivity issues to some MSN services," said an MSN spokeswoman in a statement. As of 3:00 p.m. EST, she noted that "we have begun to restore full service to some customers already, and are working quickly to take the necessary actions to restore for all customers as soon as possible."
MSN officials said MSN services began working again after a more-than-three-hour outage. The services were unavailable to some users between 12:30 p.m. EST and about 3:45 p.m. EST.
"Customers may continue to experience sporadic issues in the near term, but we anticipate having service fully restored to all customers very soon," the spokeswoman added.
Microsoft said that Thursdays outage was not related to last weeks wide-scale MSN outage. The latest outage also does not seem to be related to "any external causes including a denial of service attack or other malicious activities," the spokeswoman said.
MSN is not identifying the cause of the latest outage other than to attribute it to an unexplained "internal issue." MSN executives said last weeks outage also was due to an unspecified "internal issue" and declined to say more.
Editors Note: This story was updated with additional comment from Microsoft about the restoration of the MSN services after the outage.