The company also reported problems with its Xbox Music and Video Store services.
The service problems come on a day the company said it was recently a victim of a cyberattack similar to ones that targeted Apple and Facebook.
"Beginning Friday, February 22 at 12:44 PM PST, Storage experienced a worldwide outage impacting HTTPS operations (SSL traffic) due to an expired certificate," Microsoft said on its Windows Azure service dashboard. HTTP traffic was not impacted, the company said. It said it executed steps to update the SSL certificate and expected HTTPS traffic to notice gradual recovery in many sub-regions.
Hypertext Transfer Protocol Secure, a combination of the HTTP and SSL/TLS protocols, is an Internet communications protocol for secure network communications.
"Further updates will be published to keep you apprised of the situation. We apologize for any inconvenience this causes our customers," the company said.
Microsoft also reported problems in its Xbox Music and Video services. It said users may be unable to browse, stream, download, or buy things at the Xbox Music and Video Store, also known as "Zune Marketplace." The company did not trace a connection between the Azure storage outage and the Xbox service problems.
The company said early morning on Saturday on the Xbox support site that it is working with its team of engineers "to get those jams back online and streaming properly." The company earlier reported that users were experiencing issues accessing content in Xbox Music and Video, and said, "know that we are aware of the issue and actively engaged working toward a fix to bring you back those sweet tunes !"
Microsoft also had a serious problem in its Azure service last February.
By Saturday, the company reported that Xbox Music and Video Store were "up and running." It also said on its Windows Azure service dashboard that it had "executed repair steps to update SSL certificate on the impacted clusters," and had recovered to over 99 percent availability across all sub-regions, but warned customers of intermittent failures for the next 24 hours. "We will continue monitoring the health of the Storage service and SSL traffic for the next 24 hrs," it said.
The company has not disclosed what led to the expired SSL certificate or the service problems on Xbox Music and Video Stores. Microsoft could not be immediately reached for comment.