This is for windows XP service pack 2 - although it should work for any XP, windows 2000 versions (and possibly Vista).
If you get this error (Cannot find server) in your browser - then either your network and/or internet connection are faulty. However I have had cases where the network and internet connections are working fine - so the problem is with my PC. In this case I do the following to reset my network adapters (rather than a complete reboot):
1) Start a command prompt. From Start menu select "Run...", then enter "cmd" (without quotes) and click OK.
2) Type the following command then press enter:
ipconfig /renew
That's it. Simple eh.
HTH
Tim