system won't connect to the network resuming from sleep

[benderb]

System fails to connect to the network sometimes after resuming from sleep. Especially if the prior wi-fi network is unavailable and it needs to connect to another.

[BeemerBiker]

Disable fast boot:  That feature is loading an image of the OS and that image has the Wi-Fi disabled.

Disable fast start
To disable fast startup on Windows, open the Control Panel, navigate to Power Options, then "Choose what the power buttons do," and under Shutdown settings, uncheck the "Turn on fast startup" box; if the option is greyed out, click "Change settings that are currently unavailable" first.

Re-enable fast startup once system starts working

Prevent this from occurring again by disabling sleep for Wi-Fi.

your Wi-Fi device is not waking up properly when the computer wakes up from sleep or hibernation.

The Wi-Fi device may have a Power Management feature as shown below. If you un-check the box "Allow the computer.." then the Wi-Fi device will be enabled during sleep and will not have to be woken up when the computer resumes from sleep. Laptops in modern standby will be missing the following option.