Quentin,
That is an interesting predicament, but here are some settings you can look at.
In an elevated prompt or terminal, type in gpedit and press enter. The good thing about GPedit or the Local Group Policy is that these settings apply to all users. Important if you have separate administrator and daily standard user accounts or share this with others.
- Under Computer Configuration, expand Windows Settings > Security Settings > Local Policies > and then select Security Options. Look for "Interactive logon: Machine inactivity limit" and double-click. Do not configure this or set this to 0 (zero) if you never want the computer to go to sleep. I recommend settings this to 900 seconds (15 minutes). I would not go above 1800 seconds personally. (This may override all subsequent settings)
- Next, expand Administrative Template on the left pane and then expand System > Power Management > Sleep Settings. Look for "Require a password when the computer wakes (plugged in) and set to Enabled.
- Look for "Require a password when the computer wakes (on battery)" and set to Enable.
- Then set the next two policies, "Specify the unattended sleep timeout (plugged in)" and "Specify the unattended sleep timeout (on battery) and mirror the same seconds as the #1.
- Also set "Specify the unattended sleep timeout (both battery and plugged in), mirroring the machine inactivity time.
- If you wish to allow application to prevent sleeps, i.e. VLC Player, then configure "Turn on the ability for applications to prevent sleeps transition (both plugged and battery)" to Enabled.
- After, click the Video and Display Settings on the left pane and set the "Turn off the display" policies.
Let me know if that works for you or not. If it does not help, I will keep looking or maybe someone else has a suggestion.
Cheers, Justin