Prior to releasing Windows 8, Microsoft claimed that all WinRT apps are cleanly removed from your computer after uninstalling them, and that WinRT apps should not interfere with other running applications, because they are ran in a "sandboxed" environment. Microsoft has also claimed numerous times on Channel9 that Windows 8 apps are not ran in a VM. So my question is; are these claims accurate? If the application is not running inside of a VM, how is it possible to protect the system against malicious code at runtime, assuming the attacker was able to bypass the screening process of the Windows Store system? Microsoft allows "native code" in WinRT apps, so wouldn't it be possible (using hand-coded assembly or some odd pointer manipulation trick to call functions outside of the sandboxed environment and interfere with the rest of the system, if it's really "native code" and not some VM?