It's simple! Just follow these 6 steps to get an activatable serial number for Longhorn Server: 1. Click to enter. 2. After logging in, click on Invitations in the left-hand navigation menu. 3. Enter the invitation ID: TE06-KVM4-3RM9. 4. After filling out the form, click on the Product Key under the Windows Server "Longhorn" Pre-Release Home in the left-hand navigation menu. 5. Click "Request a New Product Key". 6. Click "Get Key".