There may a conflict on your network, please try restarting your modem, router, network and computer first. Check that connections aren't loose, such as antennas or ethernet cables. Test different cables with all ports on the router/modem connecting to the computer for connection. Use a reputable malware/virus scanning application and attempt a full system scan with all scanning options enabled before continuing on to the next step. 

Try removing any saved connections from your list of known networks:

If you're still having issues please copy and run the following commands in an elevated command prompt:

If needed please restart after running each command

ipconfig /release

ipconfig /renew

ipconfig /flushdns

ipconfig /registerdns

netsh winsock reset

If running these commands does not resolve the issue, check your time/date settings to make sure it is up to date. Last thing to try is reinstalling your network/Wi-Fi drivers.