After an extended period of inactivity, PC systems seem to lose their network connection.

Part 1: Prevent the computer from turning off wired & wireless connection after sleep 

1. Click the Start button
2. Search for Device Manager
3. Expand the Network adapters option to see all the devices under
4. Right-click your wireless and Ethernet controller 
5. Select Properties
6. Select Power
7. Make sure the checkbox for Allow the computer to turn off this device to save power is turned off

Part 2: Adjust power setting

1. Go to Control Panel
2. Edit Power > Plan Settings
3. Go to Change advanced power settings
4. Adjust Power Saving Mode for Wireless Adapter Settings to Maximum Performance
5. Change the setting for Hard disk to Turn off hard disk after 0 minutes