To avoid connection failures requiring reboot of a Windows PC upon resuming from sleep/standby, consider disabling Windows Modern Standby (formerly known as Connected Standby) during sleep. Modern Standby uses WiFi, Ethernet or other connections, periodically rousting the laptop from deep sleep to sync email and fetch updates. Only certain PCs are capable of having network connectivity during sleep. Some PCs lockout (make invisible) the Modern Standby option since there are firmware bugs that would keep the laptop awake (Dell XPS for example). The option to disable Modern Standby is only present if the laptop supports it and the OEM hasn’t disabled it.

Advantages of disabling Windows Modern Standby:

• save battery by not having your computer connected to Wifi while sleeping.
• not connecting to possibly rogue AP as you travel about, or being subject to tracking.
• some hardware (e.g. Microsoft Surface Pro) often fails to connect to Wifi on wakeup until manually going to Device Manager and disable/enable cycling the Wifi adapter.

Windows Wifi power setting is under the Control Panel → System → Power & Sleep. If present, uncheck under “Wi-Fi” the “stay connected…sleep” options.

Check configuration: from Command Prompt, type:

powercfg /a

if the response includes

Standby (S0 Low Power Idle) Network Disconnected

then the PC is set to disconnect from WiFi on sleep. This command works even if the OEM has hidden the option in the Control Panel (like Dell XPS).

SleepStudy tool

To help diagnose problems with Modern Standby, Windows provides from the factory the SleepStudy tool, invoked by:

powercfg /sleepstudy

This outputs an HTML report–copy and paste the filename from the Command Prompt into your web browser. The filename is like “%WINDIR%/System32/sleepstudy-report.html” The Windows SleepStudy report contains a great deal of nerdy but useful power system info, including battery life state.