Hi, Michael Homeister
Most firewalls would ask you, if you would like to allow the "hfs" program to connect to the internet. At the time it asks you that question, you can say "Yes". If you said "No", you can still open the firewall program and look for the "hfs" or similar name listed as not allowed to access the internet and you can just change that to "Yes" allow that program to acces the internet.
One other thing. I think you have to be sharing something before someone else can see it. You can run a simple test youreself. Just run the "hfs" program and select something to share. Then use the Browse option so that you can see the contents that are being shared. If you see the things that you want to share on your Internet Explorer Browser , then some one else, for example your friend should be able to see it when you send him the IP that "hfs" is telling you to use. Good luck.
Shodan