Machine-readable media, methods, apparatus and system for booting a processing system are described. In an embodiment, whether an encrypted version of a closed operating system is authentic may be determined. The encrypted version of the closed operating system may be decrypted with a key retrieved from a processor register to provide the closed operating system, based at least in part on a determination that the encrypted version of the closed operating system is authentic. Then, whether the closed operating system is authentic may be determined and a virtual machine may be created so that the closed operating system may be launched in the virtual machine, if the closed operating system is authentic.