So, I use Internet Connection Sharing to connect my PC to the internet via my laptop, since all wireless nics I've tried on my PC suffer from frequent packet loss while my laptop is fine, and my living situation doesn't allow me to connected wired.

The problem started only recently, and it had been running fine for months beforehand. I have checked all the services listed on various websites when I google the error message. They're running. Yes, this includes Windows Firewall. Yes, I set the LAN connection on both computers to find IP address by default. Yes, I have a second connection I'm trying to share on one of the computers. Yes I've tried restarting the computer. Both of them. Especially the one having the error.

Nothing is working. This is very frustrating.