Yes, there are several techniques to permanently disable a computer's internet access without damaging the hardware. These methods generally include: 1. **Operating System Settings**: In the operating system's network settings, the network adapter can be disabled or the network connection configuration can be deleted. Although users can re-enable these settings, if the need is "permanent", more stringent management can be implemented, such as limiting network access through system policies. 2. **Firewall Rules**: By configuring the firewall, rules can be created to block specific devices from accessing the internet. These rules can be set on the router or local computer to limit their traffic. 3. **Router Settings**: On a home or office router, MAC address filtering can be set for specific devices, or their internet access can be disabled by IP address. 4. **Network Control Software**: Access control can be implemented using third-party network management software. This software usually allows administrators to set access restrictions, which can achieve the effect of "permanently disabling". 5. **Physical Isolation**: Although this involves some hardware manipulation, you can consider physically removing the network adapter or using a physical switch to disconnect. If absolute isolation is really needed, this method is most effective. It should be noted that "permanent" in these methods depends on how you define it. If someone with the required permissions gains access to the device or network administration in the future, they may still be able to restore internet access. Therefore, a truly permanent disablement may require a combination of methods.