If you don't want your computer to be on a network, you can disconnect it without having to unplug any cables. You can also disconnect your computer from shared network drives that you no longer use.
Open Network Connections by clicking the Start button , clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.
Right-click the network that you want to disconnect from, and then do one of the following:
For a wireless, dial-up, virtual private network (VPN), or incoming connection, click Disconnect.
For a local area network (LAN) connection, click Disable.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
If you disable a LAN connection, the network adapter is disabled until you reconnect.
Open Computer by clicking the Start button , and then clicking Computer.
Click the Tools menu, and then click Disconnect Network Drive.
If you don't see the Tools menu, press ALT.
Click the drive that you want to disconnect from, and then click OK.