I am working on a drupal site which I checked out (svn) to my localhost.
Now the problem is that when I go to:
http://www.site.com
Have you checked your window's hosts file? Not sure about where it lives in Windows 7, but in XP it lives here:
C:\WINDOWS\system32\drivers\etc\hosts
Make sure there is an entry like this:
127.0.0.1 localhost
As a double-check, you may want to flush your PCs DNS cache. Go into the command line and type:
ipconfig /flushdns