The Redmond, Wash.-based software giant said that personal data such as contacts, photos and calendar entries saved remotely at its servers was recovered.
"We are pleased to report that we have recovered most, if not all, customer data for those Sidekick customers whose data was affected by the recent outage," said Roz Ho, Microsoft's vice president of Mobile Experiences. "We will then continue to work around the clock to restore data to all affected users."
Microsoft said it will begin restoring users' personal data "as soon as possible," adding it now thinks that only a minority of Sidekick users were hit by the data loss.
The fix comes after Microsoft suffered a server failure on its main and backup databases supporting Sidekick. The company said it has taken steps to strengthen its service, integrating a more resilient back-up process.
