Commerce Server 2007 Starter Site CTP
Go to https://connect.microsoft.com and sign-in using your Passport Account. If you don't have a Passport Account, there will be a link on that page to create one.
After sign-in:
If you are an existing beta tester from the CS2007 beta program, you can click on "My Participation" link in the menu on the left side of the page. The next page will display a list of programs and you can click on the link marked "CS2007 Starter Site CTP" to access the CS2007 Starter Site CTP home page. You can then click on the "Downloads" link on the left side of the page, which will load a page showing all downloads currently available on the site for Commerce Server.
If you have not participated in the Commerce Server beta program, you will need to choose CS2007Starter Site CTP from the list of available programs by clicking the link for "Available Connections" in the menu on the left side of the page. From the list of available programs, click on the link to "Apply" next to the CS2007 Starter Site CTP. After completing registration, you will be automatically given access to the Connect site to download the starter site. From the CS2007 Starter Site CTP home page you can click on the "Downloads" link on the left side of the page, which will load a page showing all downloads currently available on the site for Commerce Server.