If you have installed a new modem, you can consider several options for your old modem:

1. Return to the provider: Some internet providers offer a return program for old modems. You can contact your provider and ask if they have a procedure for returning old equipment. They can provide you with instructions on where to send the modem.

2. Drop off at a recycling center: Another option is to take your old modem to an electronic recycling center. This ensures that the materials are recycled responsibly and do not burden the environment. You can find information about nearby recycling centers through your municipality's website or environmental organizations.

3. Donate or sell: If your old modem is still in good condition, you might consider donating it to a charity or selling it to someone who can use it. There are online platforms where you can sell used electronics, such as marketplaces and auction websites.

4. Reuse: If you're creative, you can repurpose your old modem for other uses. For example, as a network switch or as part of a home network experiment. There are various online resources with ideas and guides for reusing old electronics.

It's important to ensure that you remove all personal information from the old modem before disposing of or selling it. This includes resetting the modem to factory settings and erasing any stored data, such as Wi-Fi passwords or login credentials.

Consult the modem's manual if necessary, or contact the manufacturer for specific instructions regarding the removal of personal data and the proper disposal of the modem.