From Uncorrupted Hosting Blog: ((Emphasis added.))
You can test everything by editing the hosts file on your PC
Go to: C:WindowsSystem32driversetc and open up the hosts file with a text editor, go to the end of the file and type the IP address of your new server, press tab & type your domain name, save the document, close your web browser, and clean your DNS cache (click start, click run type ipconfig /flushdns & press enter). Next, open your browser and go to your site – everything should work. When you’re done testing, delete the lines you added to your hosts file and then save/close it.
At this point, all that’s left to do is change the DNS servers for your site and point them at the DNS servers provided by your new host.
Using this approach, you can test a database driven site (like WordPress) on a new host before officiallygoing live at the new host. Always allow overlap between your old hosting account and new hosting account to make the move more seamless!
For my Mac friends, find your host files in the /etc folder. To access this file in Finder to to Go > Go To Folder, and type in /etc. ((Thanks to Mac Tips & Tricks for the info.))
When you’re done, delete that entry in your hosts file, and you’ll see what everyone else does when going to that domain.
