Microsoft: We've recovered most Sidekick data

Microsoft said Thursday that it believes it has recovered most of the Sidekick data that it initially feared might have been permanently lost.

"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," corporate vice president Roz Ho said in a letter to customers."We plan to begin restoring users' personal data as soon as possible, starting with personal contacts, after we have validated the data and our restoration plan. We will then continue to work around the clock to restore data to all affected users, including calendar, notes, tasks, photographs and high scores, as quickly as possible."

On Wednesday, at least two lawsuits were filed against Microsoft and T-Mobile over the Sidekick outages, which began at the beginning of the month with data service interruptions and have left many users without access to their address books.

Microsoft had said on Saturday that it believed all data that was not on users' phones was probably permanently lost. However, by Monday it was sounding more optimisitic it could recover the data.

Here's the full text of the letter:

Dear T-Mobile Sidekick customers,

On behalf of Microsoft, I want to apologize for the recent problems with the Sidekick service and give you an update on the steps we have taken to resolve these problems.

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. We plan to begin restoring users' personal data as soon as possible, starting with personal contacts, after we have validated the data and our restoration plan. We will then continue to work around the clock to restore data to all affected users, including calendar, notes, tasks, photographs and high scores, as quickly as possible.

We now believe that data loss affected a minority of Sidekick users. If your Sidekick account was among those affected, please continue to log into the T-Mobile Sidekick forum at http://www.t-mobile.com/sidekick for the latest updates about when data restoration will begin, and any steps you may need to take. We will work with T-Mobile to post the next update on data restoration timing no later than Saturday.

We have determined that the outage was caused by a system failure that created data loss in the core database and the back-up. We rebuilt the system component by component, recovering data along the way. This careful process has taken a significant amount of time, but was necessary to preserve the integrity of the data. We will continue working closely with T-Mobile to restore user data as quickly as possible. We are eager to deliver the level of reliable service that our incredibly loyal customers have become accustomed to, and we are taking immediate steps to help ensure this does not happen again. Specifically, we have made changes to improve the overall stability of the Sidekick Service and initiated a more resilient backup process to ensure that the integrity of our database backups is maintained.

Once again, we apologize for this situation and the inconvenience that it has created. Please know that we are working all-out to resolve this situation and restore the reliability of the service.

Sincerely,

Roz Ho

Corporate Vice President

Premium Mobile Experiences, Microsoft Corporation

Update 10:10 a.m.: Amended letter to include Microsoft's final wording of letter, which said it believes it has recovered "most, if not all" data.