There are a lot of troubleshooting steps for connectivity issues that you can try if your basic troubleshooting doesn't work.
To repair winsock on a computer that is running Windows XP with sp2, click 'Start', click Run, then type:
netsh winsock reset
Click Start, click ‘run’, type ‘cmd’ and then click ok.
At the command prompt, type the following:
netsh int ip reset resetlog.txt
And then, press enter.
....More to be updated