Looks like the server is not running... did you start it?
from the installation docs:
We can't properly talk about the launch of EasyPHP, it's only the
fact of starting the Apache and MySQL server. After the installation, a
shortcut to EasyPHP is created in the directory
"Start/Programs/EasyPHP". Once EasyPHP is launched, an icon is placed
in the System Tray. Click on it to access on the different menus :
· Log file: reporting every generated errors from Apache and MySQL
· Configuration : a simple interface to configure EasyPHP
· Web local : open the URL "http://localhost/"
· Start/Stop : start/stop Apache and MySQL service
· Quit : do I need to explain? :p