Winsock entries tells Windows 7 how to access your network services. Additionally, your TCP/IP protocol can be corrupted. The TCP/IP protocol is a stack of 4 layers that includes several transport layers, but when this stack is corrupt you will constantly have connectivity issues.
So to fix this problem is may work if you reset winsock and the TCP/IP stack.
Copy/paste the following two commands, one at a time, into an elevated command prompt hitting enter after each one, then reboot your machine and test connection.
(reset winsock entries)
netsh winsock reset catalog
(reset TCP/IP stack)
netsh int ip reset reset.log hit