Let's try these options to fix the wifi problem:
1. make sure you have not disabled the wifi by mistake. so you need to press the wifi button to enable to WiFi.
2. also check, if you have disabled the wireless adapter by mistake.
3. If your laptop is still not allowing you to access the wifi network. you need to uninstall the wifi driver from your computer and install it again. i am sure your network will start working fine.