If you need to recreate the CEM web site use the following steps:
1. Stop the Altiris Service
2. Remove the site from IIS
3. Delete the HKLM\Software\Altiris\NS Agent Site.
4. Go to the HKLM\Software\Altiris
5. From the above location in step 4 delete the AgentWebSite value
6. Delete from "HKLM\Software\Altiris the tsSecondaryWebSite value.
7. Run an 'iisreset' and then Restart the Altiris Service
8. Go to the Settings>Notification Server>Cloud-enabled management>Setup>Cloud Enabled Management Agent IIS Settings
9. Check the box to add an IIS web site and make sure you use the appropriate certificate and click save