O que eu gostaria de fazer é alterar a hora padrão em que o Windows define a reinicialização para ocorrer
Como você observou corretamente em sua pergunta, o tempo de reinicialização padrão é às 3h30.
As instruções a seguir mostram como alterar o tempo de reinicialização.
Windows 10 now allows you to specify a time for the computer to reboot after updates are installed to finish the installation.
To schedule a restart for updates:
Click the "Start" menu icon and select "Settings" on the Start menu.
On the "Settings" screen, click "“Update & Security".
The "Windows Update" screen displays by default.
- If you have updates available, Windows will start downloading them and preparing to install.
- Click the "Advanced options" link.
- The update process will continue even though you are leaving the main "Windows Update" screen.
On the "Advanced Options" screen, select "Notify to schedule restart" from the drop-down list at the top of the screen.
Click the left arrow button in the upper-left corner of the screen to return to the "Windows Update" screen.
You are notified that a restart has been scheduled and options are provided for you to schedule a time for the restart to happen.
- The first option provides a suggested time to restart the machine to finish installing the update.
- To specify a different time and date, select the "Select a restart time" option and specify a "Time" and "Day".
- For the "Time", click the box, hover your mouse over each part of the time (hour, minutes, and AM/PM) and scroll through the options until you reach what you want.
Note:
When you choose "Notify to schedule restart" you will be prompted via a system notification to select a specific restart time every time an update has been downloaded and your PC needs a reboot.
- This tweak does not pause update restarts, it only notifies you that a restart is required soon. Windows will schedule its own reboot first, and you must override it manually by scheduling your own.
- There should also be a "Restart Now" link you can click to restart the machine now to finish the updates immediately.
Fonte Como agendar reinicializações para atualizações no Windows 10