Allowing restarts to occur without user interaction has helped us to rapidly update a major portion of the Windows ecosystem with critical updates. On average, within a week of releasing a critical update, 90% of PCs have installed the update (see Figure1). On the other hand, this behavior of automatic restarts has some unintended consequences for the user. Restarts can occur without notice, and might occur monthly or even more often if there is an out-of-band update. This unpredictability can potentially result in loss of user data. Most of our automatic installs and the subsequent restarts happen at 3 AM, when users are not around to save any important work. We have heard a lot of painful stories of users coming back to their PCs in the morning to find that a restart occurred, and that some important data was lost. In other cases, the user doesn’t lose data, but needs to restart a job that they were in the middle of (for example, a long copy job).