Windows 7 x64 permissions problem

Windows 7 x64 permissions problem

I've installed Windows 7 x64 over a previous pre-release version. What typically happens is that if you choose not to format it moves everything in existing Windows folders (Program Files, Users etc) into a folder called Windows.old. Then it creates new Windows folders and assigns Admin/System/TrustedInstaller permissions to them so that a regular user can't go about messing with system files/installed applications.