Hi,
Try these steps, to see if they can help you.
1. Open DEVICE MANAGER
2. Open up NETWORK ADAPTERS
3. Right click on the WiFi Adapter for the pc and left click on PROPERTIES
4. Click on POWER MANAGEMENT at the top.
5. Remove the check mark beside : ALLOW THE COMPUTER TO TURN OFF THIS DEVICE TO SAVE POWER
6. Click OK
7. Close DEVICE MANAGER and test.
2. Open up NETWORK ADAPTERS
3. Right click on the WiFi Adapter for the pc and left click on PROPERTIES
4. Click on POWER MANAGEMENT at the top.
5. Remove the check mark beside : ALLOW THE COMPUTER TO TURN OFF THIS DEVICE TO SAVE POWER
6. Click OK
7. Close DEVICE MANAGER and test.
NOTE: It may also be checked under the FAMILY CONTROLLER (eg. Realtek PCIe GBE Family Controller which would be listed under the WiFi Card). If so, you could remove the check mark beside ALLOW THE COMPUTER TO TURN OFF THIS DEVICE TO SAVE POWER.
Let me know if it helps.