Microsoft Live ID authentication problems hit users across the Web

Reports cropped up across Twitter around 1:30 ET on February 16 from individuals having problems logging into Microsoft's Hotmail, Xbox Live, as well as other Windows Live services.

No word yet from Microsoft on what's causing the issue, other than it seems to be connected with Windows Live ID authentication. Also no word on the scope of the problem.

LiveSide.Net is reporting that it might have been a short-lived outage hitting anything connected with the Live.com domain.

I received this statement from a Microsoft spokesperson when I asked for more information:

"We are aware that some Windows Live ID customers may be experiencing difficulty accessing their accounts, and are working aggressively to address the situation as rapidly as possible. We sincerely apologize for any inconvenience this may be causing our customers."

(Microsoft officials also tweeted this same statement via its @WindowsLive alias.)

(I'll update this post once additional info is available.)

Update (2:15 p.m. ET): A bit more info from the spokesperson:

"This morning, around 9:30am PST,  the Windows Live ID sign-in service experienced a partial outage that caused some customers to not be able to sign into services using Windows Live ID for approximately one hour. The service is now restored to normal. Microsoft apologizes for any inconvenience this has caused customers."

I've asked how many customers were impacted and what caused the "partial outage." I'll update again if I get more info.

Update: (3:20 p.m. ET): Looks like it was a server outage, the cause of which is under investigation. From a post on the Windows Live Engineering blog:

"Due to the failure of one server, Windows Live ID logins were failing for some customers, and this increased the load on our remaining servers. We took the problematic server offline and brought a new server into rotation. We identified the root cause and fixed it in less than an hour, but it took a while to resolve the logjam that had built up in the meantime, and to redistribute the load to normal levels."