Be sure that your computer and your device are on the same network.
On Windows, check your firewall configuration.
- Open the control panel.
- Click 'Windows Firewall'.
- On the left pane, click on 'Allow a program or feature through Windows Firewall'.
- Then on 'Change settings'
- Search for 'Telepad' and check the network locations you want, usually "Home/Work(Private)" will be sufficient.