When you purchase SBS 2008 along with Client Access Licenses (CALs) but need to downgrade it to SBS 2003 due to a business requirement, you won’t be able to log onto EOpen to download your media and keys.
In order to get the SBS media, you’ll need to contact Microsoft’s Volume License Fulfillment Center at (800) 336-0098 to order the disks. The installation key is included with the disk.
Need the key to install the CALs on SBS 2003? Contact Microsoft’s Volume License center at (888) 352-7140 and have your volume license order confirmation handy. They will issue your installation keys over the phone.