What to do if Wi-Fi does not work after Sleep mode
In Windows 8 and 8.1, there might be problems with connecting to Wi-Fi network after waking up the computer from the Sleep or Hibernation modes. Although the connection was working A-Okay before, after waking up the computer does not want to reconnect to the network. What should you do?
Once the computer wakes up, it should automatically connect back to your basic network. However, in some cases this might not be the case. Sometimes you need to reconnect manually, at other times you cannot connect until you reboot the computer. How to solve this problem?
1. Check whether the computer automatically connects to the network
It is possible that automatically connecting to a given network is not set, therefore, the computer does not connect to the network after waking up from the Sleep mode. When you will be connecting to your Wi-Fi network for the next time, you need to make sure that the option "Connect automatically" is marked.
2. Check if power management settings do not collide with the network adapter's
Go to the Start Screen and type in "Power management". Once you click it, you will be presented with power management settings. Go further by clicking "Change plan settings" next to your active power management plan (the one chosen from the list).
You will see the settings regarding the currently used power management plan. Click "Change advanced power settings".
In a new window, go to "Wireless adapter settings > Power Saving Mode" and in both cases switch up to "Maximum Performance". Confirm by hitting OK.
3. Block automatically disabling network adapter for energy saving
Windows has an option for automatically disabling any devices to save energy. This may collide with the Sleep mode and make the network adapter not work after waking up the computer.
To change this settings for the network adapter, go to Control Panel and then go to "Devices and sound > Device manager". On the list, go for network adapter and right-click on your Wi-Fi adapter (it should have "Wireless" or "WLAN" in its name).
From among the options available, go for "Properties". In the new window, go to "Power Management" and unckech the option "Allow the computer to turn off this device to save power".
4. (A route around) Create a shortcut for a quick reboot of the network adapter
If none of the options above seems to work, you can, ultimately, create a desktop shortcut to use once you wake up the computer from the Sleep mode. This shortcut will reboot the network adapter so you will not have to reboot the whole computer. Once the network adapter is restarted, your computer will be able to connect to wireless networks.
This shortcut will lead to the following location:
C:\\Windows\System32\WindowsPowerShell\v1.0\powershell.exe restart-netadapter - InterfaceDescription 'YOUR NETWORK ADAPTER'S NAME' -Confirm:$false
The first thing you have to do is to obtain the full name of your network adapter to paste it into the bolded place above. Using the instructions from point 3, go to the Device Manager and look up your network adapter on the list. In my case, it is "Network adapter Dell Wireless 1490 Dual Band WLAN Mini-Card". Type (or paste) this name like this:
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe restart-netadapter -InterfaceDescription 'Dell Wireless 1490 Dual Band WLAN Mini-Card' -Confirm:$false
Now you need to right-click on the Desktop and choose "New > Shortcut".
Paste the code above, your network adapter name's included, into the location field above and click "Next". Call the Shortcut whatever you want (e.g., "Wi-Fi Reboot") and confirm shortcut creation. By launching the shortcut, you will make the system reboot the network adapter, making it possible for your computer to connect to the network.