1. Download and install TortoiseSVN
Standard setting during install will work
After finishing installation create a new folder in your Userdirectory. It should be located in "C:\users\username" . I called my directory "0adsvn"
Then right click on the new created directory and choose "SVN Checkout..."
In the Checkout mask just enter the URL of repository: "http://svn.wildfiregames.com/public/ps/trunk"