Sometimes when your connection drops a bad DNS entry will be cached and you will need to either flush the DNS cache to get rid of it, or wait up to 24 hours for it to be dropped from the cache automatically.
You can run this small batch file I put together every time your connection drops or when you are having problems like ‘Server not found’.
Simply open up Notepad, paste the text below into it and save it as connectionfix.bat.
@echo off ipconfig /release ipconfig /flushdns ipconfig /renew ipconfig /all pause
Just run it whenever you are having connection, DNS, IP or server problems.