This short guide will show you how to delete, or "forget," a saved wireless network from your Raspberry Pi. This is useful for changing networks or troubleshooting connectivity issues.
To forget a specific Pi wireless network, delete the corresponding network block, surrounded by opening and closing {} curly braces. For example, deleting the following will "forget" the serenity network:
If you want to forget a network but keep the configuration in place for later, you can uncomment the block instead by adding a # symbol to the beginning of each line. For example, uncommenting the following will "forget" the serenity network while keeping the details in the file for future use:
When you're done, save and exit by pressing CTRL-X, typing Y, and pressing enter.
A recommendation before deleting
Of course, if you're connected to your Pi via the network you want to remove, you'll be disconnected from the Pi as soon as your Pi forgets the network.
Therefore, I recommend adding a new network before deleting the other network—this makes it slightly easier to add your "new" network. If you need to, finding which network your Pi is connected to is easy.
So you've got a machine running Ubuntu. If it's been a while since you set up Ubuntu (or maybe you're just curious), you probably need to check what version you're running.