I couldn't find an accurate tutorial that was written after the implementation of systemd so here's what I found to work for my setup.
Synergy is a cross platform keyboard and mouse sharing application that you can read about on their site. The ability to use my win7 box's keyboard and mouse on my Raspberry Pi is a game changer and I will say that I purchased the Synergy software but I think you can use the free version for our purposes.
Assuming you have followed the instructions from Synergy to get the server setup on another machine you can follow these steps from the Raspberry Pi.
I'm using the "Raspbian Strech with desktop" image available from the official Raspberry Pi website along with a Raspberry Pi 3.
Install Synergy from the repository:
You should then be able to run Synergy from the main menu like so...
Add the server's IP address and take note of the client screen name to add to the server's list of acceptable clients.... This setup info can be found on the Synergy website so I won't recreate it here.
Once you have a working connection between your server and client machines we can setup the autostart script on the Raspberry Pi. It is not a good idea to attempt the autostart setup before making sure you can first use Synergy on the two machines successfully.
Open the autostart file:
Add to the bottom of the file:
Be sure to save your changes when you exit nano.
Create the script that will be initiated by the autostart file:
Put this in the new file, make sure to use YOUR screen-name where I have "raspberrypi" and your IP address as well.
Once again be sure to save your changes as you exit nano. Now the final step is to make the script you've just created executable.
Give permission to execute:
Now reboot your Raspberry Pi and you should have access from the server once the desktop is loaded.