Hi @Gghh09876,

If you don't have the old password to manage the router, switches, and APs, you gotta reset them first. This will reverse them to the factory default settings.

To reset them, you have to find the reset button on them. Press and hold 5-8 seconds, typically, they'll be reset to the factory settings. The username and password would both be "admin".

Pay attention to that during the reset, there should be no power cut. Do not move anything during the reset. This could damage the firmware and you won't be able to use them again.

After the reset, you have to config the network again. Config your WiFi again as well.

For further instructions, you may refer to the support page. Search your model and check out the support page for videos or instructions.

Support portal: https://www.tp-link.com/support/