You need to verify the IP Address of the Pi at the time you want to connect to it. You can do this by using Ping as mentioned in the comments above. A better solution would be to SSH to the Pi from Windows as this will allow you to 100% guarantee that you have the correct address for the Pi. You can download PuTTY or similar if you do not already have an SSH compatible terminal application on your laptop.
After you have verified the IP address on the Pi you should verify that the server software (you said it was mRemoteNG) is running on the Pi. I asked a similar question here: How can I get tightvnc to start automatically on startup? but I was using TightVNC software, but the same idea applies.