Sharing Wifi Internet Via Ethernet

I've got two computers in my room: a Toshiba laptop and a desktop computer (both running Windows 7) I built a few months ago. The laptop gets great wifi reception, 4/5 bars, while the desktop struggles to get one bar. I want to connect the laptop to the PC via Ethernet and use the laptop's Internet connection. I'm having troubles doing this.

Here's what I've done thus far:Disabled the desktops wifi. Enabled "Allow other network users to connect through this computer's Internet connection" on the laptop's Ethernet card. Plugged in the cable.

This is where I hit the brick wall. On both computers, it comes up as "unidentified network". I try creating a homegroup on the desktop, but I encounter an error "Windows could not set the network settings" and "You can try to change this setting later in the Network and Sharing Center." I look in the Network and Sharing Center, and it says "Homegroup: Joined" as if no error occurred at all. So I try to join the homegroup on the laptop. It says "Larry from LARRY-PC has created a homegroup" so it recognizes it, but then it says "Windows could not setup a homegroup on this computer" when I try to put in the password.

I start the HomeGroup Troubleshooter, and it troubleshoots network problems. After that, it says "Local Area Connection" doesn't have a valid IP configuration: Fixed" So then I try joining it again, and get the same issue. I go through the HomeGroup Troubleshooter again, and I click "the problem is not fixed" and get a list of problems I don't have.

What can I do?