seems like you just need to start from scratch..
Make sure you know the PLC IP Address. what is it? (If you don't know, get to the ENET config screen by using the LCD like in the videos).
What is your computers IP address on the port you're plugging in to?
make sure you have the subnet set the same. and the IP address set to the same first 3 octets, and make sure the last is NOT the same. (Example : PLC IP = 192.168.1.10, PC can be anything but 10. so the PC = 192.168.1.12 will work fine while being directly connected to it).
bring up the command prompt and try to ping the IP address by typing in - ping ***.***.***.*** where * is replaced by the IP address of the PLC. If you don't see a reply, then the network configuration needs to be solved first.
After the network configuration is good, then start rslinx, and choose 'Communications' from the bar on top. then 'Configure Drivers...'
Select Ethernet Devices from the dropdown, then click 'Add New...', and click OK for the default name (no need to change).
Click on the Empty box and type in the IP address of the PLC you are trying to connect to. then click OK and close the configure drivers window.
Now expand the Driver you added in by clicking the + next to it, or double clicking it.
you should see the PLC show up with the words ML1100 and possibly whatever the program name is in it. If that doesn't happen, and you can ping and get a good signal, then you'll need to delete harmony files to get it to discover the connection again.