We have a legacy app which writes to an .ini file in a protected location. In Windows Vista/7, we can bypass this issue by turning off UAC which in turn disables UAC file virtualization using the virtualstore. Unfortunately this does not work in Windows 8. Turn UAC all the way down and the problem still occurs. Google info is full of tips for Vista/7, but I guess as 8 hasn't hit the masses yet I haven't found a solution.
Now I know that turning off UAC is not a great idea, and is not a true solution - which would be modifying the legacy app to write to a non-restricted area. However, for various reasons this is not possible.