Look in the HOSTS files to see if there are any entries other than 127.0.0.1
Not sure if this switch is supported by W2K Server
open a command prompt and type
ipconfig /flushdns
enter
See if you can access the sites
If not type
ipconfig /registerdns
enter
Also try the sites via a proxy
http://www.anonymizer.com/
http://www.anonymization.net/