Resuming from a sleep state. A request may received to resume operation of a computer system from a sleep state to an executing state. A restoring process may be initiated to restore the computer system to an executing state. The restoring process may include loading information from a nonvolatile memory medium to a computer system memory medium. A request may be received from a processor of the computer system to access the computer system memory medium. The request may require access to a portion of the computer system memory medium in the executing state, and may be received prior to completion of the restoring process. It may be determined if the portion of the computer system memory medium has been restored. If the portion of the computer system memory medium has not been restored, the portion of the computer system memory medium may be restored from the nonvolatile memory medium ahead of other portions in the restoring process.