When trying to reinstall the Service Manager Portal\Management server you may get the following error:

So.. First, let’s remove these registry keys:

• HKLM\Software\Microsoft\System Center
• HKLM\Software\Microsoft\Microsoft Operations Manager

Next, After searching the net for hours, seeking for solution… I understood what was missing ! – Importing the Encryption key I’ve generated on the first time I installed the Service Manager:

1. Quick navigating to the installation folder of service manager -> <Installation Media>\Tools\SecureStorageBackup
2. Lunching the SecureStorageBackup.exe
3. Choose restore key
4. Load the file and enter the password…
5. Re-Start the installation

That’s it.