can't change computer name, because the option is greyed out

source

NOTE: The identification of the computer cannot be changed because: - Networking is not installed or is not properly configured.

fix:

From the Control Panel, open Network Connections.

Right-click on my active Local Area Network connection and choose Properties.

In the Local Area Connection Properties dialog, select Client for Microsoft Networks, then click Uninstall. Close the dialog and reboot when prompted.

After rebooting, bring up the Local Area Connection Properties again.

Re-install the Client for Microsoft Networks by clicking the Install button, selecting Client from the Select Network Component Type dialog, then selecting Client for Microsoft Networks from the Select Network Client dialog.

Click OK all the way back out, then reboot the machine once more when prompted.

if that doesn't work, try running a sfc /scannow, then rebooting.