Quote from potatopuppy
More specifics on this. You need to go to advanced settings on your firewall to make TCP and UDP rules.
1. Open control panel
2. Windows firewall -> Advanced settings
3. Click inbound rules
4. In the left collumn should be the new rule option
5. Make a port rule and create both a TCP and UDP rule, both on local port 25565 (or whatever port you use)
6. In the action section, click "allow the connection"
7. Keep everything checked for where the rule applies
8. Name it something you will remember and specify which is the TCP and UDP rule.
Adding TCP and UDP rules like this just fixed my server for 1.7.9 which I was having issues with yesterday. Hope this helps.
This doesn't seem to work for my, ive everything but nothing seems to work, could this problem be due to a slow internet connection?