I am facing the similar problem here.
I installed a new Windows from scratch, then BESR, then all Windows update available, finally the SEP.
The SEP installation finished smoothly. It prompted for reboot and I did so. But after reboot, SEP was actually not installed. It doesn't exists in the "Program Files" folder, or Windows' "Uninstall Programs" panel. The only thing the SEP left behind was the registry keys mentioned above.
I tried to install SEP again. An error message said that it couldn't access those registry keys.
I tried to delete those registry keys in regedit.exe, it said I didn't have access right. But I am the Administrator.
I will try Daniel's workaround later, but I would really like to know the cause. e.g. a Windows bug? SEP bug? or incompatibility between SEP and BESR?
================================================ Windows version:
Windows Server 2k8 Standard Edition SP2 x64
Windows Server 2k8 Standard Edition R2 x64
SEP version:
SEP 11 x64 ( I am not quite sure about the exact version)
Backup Exec System Recovery version:
BESR 2010