Ping the domain, take the IP address it returns then whois that IP.e.g. (this is on linux but the tools are on windows command line too)
tolan@thome:~/bin$ ping b3ta.com
PING b3ta.com (207.44.242.20) 56(84) bytes of data.
[...]
tolan@thome:~/bin$ whois 207.44.242.20
OrgName: ThePlanet.com Internet Services, Inc.
[...]
(tolan@thome:~/bin$ ping b3ta.com
PING b3ta.com (207.44.242.20) 56(84) bytes of data.
[...]
tolan@thome:~/bin$ whois 207.44.242.20
OrgName: ThePlanet.com Internet Services, Inc.
[...]
slight yoinks!,
Mon 8 Dec 2008, 14:53,
archived)