
If the option to forget the network is available, tap Forget this Network. Locate the Wi-Fi network to be removed and click the blue symbol next to the name.
To forget a wireless network on your iPhone or iPad:
Press and hold the Wi-Fi network to be removed, and then choose Forget.
To forget a wireless network on your Android mobile device:
Click -(the minus sign) to forget the network. Under "Preferred Networks", select the Wi-Fi network to be removed. At the top of your screen, click the Wi-Fi symbol and then select Open Network Preferences. In the "Manage Wireless Networks - Warning" dialog box, click OK. Right-click the connection you want to delete, and then click Remove network. In the "Tasks" pane, click Manage wireless networks. At the bottom right in the system tray, click the network icon, and choose Open Network and Sharing Center. To forget a wireless network in Windows 7: Under "Manage known networks", select the Wi-Fi network to be removed. At the bottom right in the system tray, click the network icon and choose Network & Internet settings. To forget a wireless network in Windows 10: