What I sometimes do for other people's tuning computers is if they had "access rights" issues, (Windows 7 is famous for this) I went and set any efi live application (V7.5 tune and scan, V8, explorer etc..) to run with full admin rights.. You don't want to run your computer as local admin full time because if you get any virus(es) while logged in as the local admin the virus(es) use your access rights to gain access to the entire hard drive directory and can edit or delete what ever it wants..
I own a computer repair and custom PC build shop.. I've saved many computers by doing this.
Is it not letting you open the scan tool?
Is this a first time install on this computer?
Have you tried reinstalling it? maybe a bad install? Ive seen installs go bad not just with EFI live but other programs.