Why does RealVNC say connection timeout?

Question

I can connect my desktop to my laptop but when i try the reverse the laptop says "connection timed out"

Answer 1

Are you running VNC Server on the desktop?

Answer 2

Assuming there's no other connectivity issues... Check to see if the desktop has a firewall up.  Windows firewall may block vnc by default,

Answer 3

All VNC type systems require that the "server" be running on the target machine.

When you connect your desktop to the laptop the "server" is running on the laptop and you use the "viewer" to connect to the "server"

To connect the other way you need to start the server on the target machine first