In a process for hot-swapping operating systems, an original operating system (OS) instance is executing on and controlling hardware of a computer. The original OS instance generates updated launch code that defines a division of the hardware into a source logical partition and a target logical partition. The original OS instance quiesces processes hardware of the target logical partition so that the original OS instance and an application running thereon are contained by the source logical partition. The original OS instance launches the updated OS instance so that it executes on the target logical partition. The application is moved from the source logical partition to the target logical partition. The original OS instance terminates. The updated OS instance claims hardware freed by the termination.