The WoW64 subsystem is limited to the so-called user mode, i.e., applications launched by the user. When operating in kernel mode, all files have to be available in 64 bit format.
Since all device drivers require kernel-mode access, it is no longer possible to use 32 bit drivers, even if they were written specifically for Windows Vista. Also, not all device drivers that Microsoft offers through Windows Update are available as 64 bit drivers. This also includes devices that you may be used to attaching quickly and simply via USB.
Especially problematic are more exotic devices, such as older scanners or COM-port adapters; these may encounter driver problems and may thus not be usable under 64 bit Windows.
CoreTemp won't run in the standard Windows configuration
Without a proper driver, the application is unable to display any readings.
In some cases, you may need device drivers even without using hardware. One such example would be applications that read data from the CPU or memory using the SM-Bus. While CPU-Z and Speedfan ran flawlessly, we had to disable driver signatures for CoreTemp, even though it possesses a 64 bit driver component. Copy protection drivers used by older games may also cause problems. Games that carry the "Games for Windows" logo, on the other hand, are safe and will run smoothly.