Skype and firewalls
1. Open Windows Firewall (Start > All Programs > Control Panel).
2. Double click on Windows Firewall icon to launch it.
3. Make sure the check box for “Don’t allow exceptions” is unchecked.
4. Click “Exceptions” tab to open it.
5. Click on the “Add Program…” button below the list of Programs and Services.
6. Select Skype from the list and click OK.
7. Click OK to confirm your settings.
Congratulations, you have successfully updated your Windows Firewall.
Restart Skype, it will automatically reconnect (this can take up to two minutes).
If Skype cannot still connect, try restarting your computer or contact your system administrator or ISP for further assistance.