Cannot upgrade 7.5 to 7.6

I attempted the upgrade just now and it failed at the 'Preparing upgrade of additional components' section which i understand is due to the fact that iam not logged in as the user who did the initial install. So i downloaded the Fix 7.5 Installer Tool. The tool wont work however, i get an error stating 'Did not detect a 7.5 installation, aborting'.

Can anybody help me with this?

Thanks