Sharing network connection between a Windows and a Ubuntu PC

Hi. I am trying to share an internet connection between a Windows 8.1 laptop and a Ubuntu 16.04 desktop. I have Internet Connection Sharing enabled for the Windows laptop and the Ubuntu desktop connected to the laptop's Ethernet port, but the Ubuntu PC just doesn't get an Internet connection. Can anyone please help me? Thanks.
 
Solution
Have you adjusted the TCP/IP4 settings on the Ubuntu machine to match those on your laptop?

First find out what IP address your laptop is receiving from your router/wifi connection. To do this go to:

Control Panel>Network and Internet>Network and Sharing Center>Wifi>Details

Look at the IP Address of your laptop, write it down.

Go to your Ubuntu desktop and assign it a static IP that is in the same range as the one on your laptop. (for example, if your laptop is 192.168.1.51, then make the Ubuntu desktop 192.168.1.60).

Jester Maroc

Distinguished
Have you adjusted the TCP/IP4 settings on the Ubuntu machine to match those on your laptop?

First find out what IP address your laptop is receiving from your router/wifi connection. To do this go to:

Control Panel>Network and Internet>Network and Sharing Center>Wifi>Details

Look at the IP Address of your laptop, write it down.

Go to your Ubuntu desktop and assign it a static IP that is in the same range as the one on your laptop. (for example, if your laptop is 192.168.1.51, then make the Ubuntu desktop 192.168.1.60).
 
Solution
Now there's another problem:
I turned off both systems and left them off throughout the night. I turn both back on this morning and now the Ubuntu PC doesn't have an Internet connection. The laptop has the same IP address as before, and can load webpages(I'm posting from it right now.) I've set the Ubuntu box's IP to the same as the laptop's, put a subnet mask(it connected w/o one yesterday) and even setting the IP at the end of the range. It still won't connect. What happened, and why, and how do I fix this?