Installing XTU, "verify that you have sufficient privileges to install system services"

Hello all, I am encountering the following issue when trying to install XTU, "verify that you have sufficient privileges to install system services".

I am trying to install on a newly purchased Asus ROG G751JT running Win 8.1. I have been trying to sort this out for days and its driving me crazy!!


I have tried everything I know over the past 24 hours but to no avail and your help would be much appreciated.
 
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