1. A computerized method for resuming or launching a virtual machine, the method comprising: disabling interrupts by clearing an interrupt flag to prevent a host operating system from controlling a first hardware thread of a plurality of hardware threads; loading a first virtual machine context; setting the first hardware thread to the state of a first guest operating system, wherein the first guest operating system executes within the first virtual machine context; resuming or launching the first virtual machine context; saving the state of the first guest operating system locally; performing a context switch to the context of a virtual machine monitor, wherein the virtual machine monitor executes under the host operating system and the virtual machine monitor schedules the first virtual machine context; clearing the first virtual machine context from the first hardware thread; and setting the interrupt flag to allow the host operating system to control the first hardware thread.