Go to C:\Windows\System32\Drivers\etc\
In this directory is a file called "hosts"
Open it with Notepad.
At the end of the file you should see something like: 127.0.0.1 localhost.
Below that line, add the following:
You can add other domain names the same way
Save the file. Make sure you do not have any extensions such as "txt".
You need administrator rights to save files in this folder.