We explain the difference between Home and Public networks in Windows
QUESTION My Windows network is configured as a home network, which I assumed would be more secure than a public network. I thought my network would be hidden, yet I can see other networks alongside mine. Is this dangerous?
HELPROOM ANSWER We can see why you might think a public network setting would be less secure than a home network, but it's actually the other way around. The different network types are designed to match the locations in which you're using your PC; rather than opening your network to all around, a public network will offer greater protection than a home network when you're out and about. In fact, it's the safest Windows network setting that you can use.
The Home network setting is for use only when your computer is in the relative safety of your own home and you want to communicate and share with other PCs as well as the internet. Don't worry about the Work network option. This is similar to the Home setting, but it's designed for corporate domains.
If you're at home and unrecognised computers are showing up on your network, ensure that WPA (or preferably WPA2) encryption is enabled on your router. As an extra precaution you could also change the password.
It's more likely that the other 'computers' you're seeing are in fact nearby wireless networks. It's normal for several to be in range, especially in densely populated areas. These pose no security threat to you.