Registry Keys Missing

Hi,
During my total FS 2004 de-install (had it installed on C drive, not in the program files!) as per the Microsoft 'manual remove 'guide http://support.microsoft.com/kb/888846, I noted that the local machine registry keys due to be removed (in bold below) were not there, therefore obviously could not be removed:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Games\Flight Simulator\9.0
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ Uninstall\Flight Simulator 9.0
The keys in the current user registry were there and could be removed.
HKEY_CURRENT_USER\Software\Microsoft\Microsoft Games\ Flight Simulator\9.0

Any thoughts on this, in particular; why were these keys missing? Could they be hidden someplace else in the registry and be removed from there?
Any help much appreciated.
Regards
Peter