Can connect to other computers but they can't connect to me...

So my PC has never had any issues with getting connected to in the last 5 years of having TV on it. All of a sudden when I try to connect to it from any other computer or phone is just sits on "connecting" for a few minutes then just stops. I uninstalled and reinstalled TeamViewer and it hasn't helped. I'm able to connect to other computers from that PC easily, but cannot connect to it. Its status says "ONLINE". What else can I try?