It's worked!! Thank you very much for your help. Really appreciate it.
So, i know where i made the mistake. In doing my research earlier this week, following the two reinstalls and finding that the 'Security Health' folder was empty, i reverted to search for solution online. I found your message above ref downloading the files and the ExecTi solution (the second option) which i tried and manually placed the files into windows folder as per directions. This solution failed, based upon the fact that the system recognised a newer version on my pc when i tried to reinstall the first package, and later running the SecurityHealthSetup.exe under admin had shown the CMD screen, and following restart, yet again failed to allow windows security to work- i.e. showing blank screen.
SOLUTION FOR OTHERS WITH SIMILAR ISSUE...
Use _AW_ method of ExecTI to delete the files [if manually inserted] within the SecurityHealth folder (if you made a similar mistake to me), in addition to the folder in 'C' root where i had originally saved them. Reboot. Run the SecurityHealthSetup.exe as administrator, as advised by _AW_. Reboot...and..it works! :)
Thank you again.