Boot-time optimization
Boot-time optimization runs O&O Defrag in Fortress Mode, its own start environment based on Windows Recovery Environment (Windows RE). Normal Windows applications are not running there, so eligible files that are locked during ordinary Windows use can be optimized.
Every run is a one-time action. On Boot-Time Optimization, choose how it runs (Automatic or Manual) and when (Restart and optimize now or At next system start). A scheduled run applies to the next system start only. For another run, start or schedule it again.
Requirements
You need the full version, administrator access, a usable Windows RE installation, and sufficient free space to prepare the optimization environment. The page checks recovery-environment readiness. If prompted, restart O&O Defrag with administrator rights and repeat the action.
Make a current backup before intensive maintenance. Save all work before restarting and allow a maintenance window during which the computer will be unavailable. If BitLocker is in use, read the BitLocker guidance before scheduling or starting a run.
Prepare and select drives
- Open Boot-Time Optimization.
- Review the Windows Recovery Environment readiness result.
- In the Fortress Mode row, choose Set up. If the environment was prepared for an older program version, choose Update instead.
- Wait until the status shows that the environment is set up for the current version.
- Choose Automatic and select the drives to optimize, or choose Manual to select your operations later in Fortress Mode.
Set up the environment once per program version. Setup alone does not restart the computer or schedule an optimization. After a program update, update the environment when requested, then start or schedule a new run.
Choose automatic or manual operation
| Mode | What happens in Fortress Mode |
|---|---|
| Automatic | The selected drives are optimized using SOLID/Quick without interaction. The computer returns to Windows after the last drive finishes. |
| Manual | O&O Defrag opens and waits for you. Choose the drives and optimization operations there. Closing O&O Defrag starts Windows. |
In Automatic mode, drive selection is saved immediately, including changes to a run that is already scheduled. Clearing every drive selects the Windows system drive as the fallback; it does not cancel the run. Changing the mode also updates an already scheduled start. Choosing a mode or drives alone does not schedule anything.
Schedule the next system start
- Choose the mode and, for Automatic, review the selected drives.
- Select At next system start and respond to any BitLocker prompt.
- Check the status banner: it shows the automatic run and its drives, or the manual start into Fortress Mode.
- Continue working and restart the computer when convenient.
This action schedules one start without immediately restarting the computer. The boot-time status on Overview reflects the same schedule. If nothing is scheduled, Windows starts normally.
Restart now
Choose Restart and optimize now to run the selected mode immediately. Read the confirmation and confirm only when ready to restart. If a run was already scheduled, this restart uses that run; it does not add another one for a later start. See Fortress Mode for the restart sequence and BitLocker considerations.
Cancel a scheduled run or remove the environment
Choose Cancel scheduled optimization to cancel the pending start. Check that the status says nothing is scheduled. Fortress Mode stays set up for future use, and Windows starts normally next time. This button cancels a pending run before the restart.
To remove the prepared environment as well, choose Remove in the Fortress Mode row and confirm. Removal also cancels a scheduled run. You can set up the environment again later. See BitLocker guidance for protection handling when cancelling.
When preparation fails
Do not force a restart into an environment that failed preparation. Check the displayed error and logs. Possible causes include missing recovery files, insufficient system-drive space, a failure to mount or save the recovery image, or an incomplete installation.