Even the most corrupt of installations-which can lead the app to refuse to launch existing VMs or create new ones, or seemingly lock the administrator out of the hypervisor altogether-may be overcome with a little careful pruning that uninstalling the application and reinstalling it don't seem to quite clear out.

SEE: 10 essential apps and utilities for your Mac (free PDF) (TechRepublic) The real issues that can grind Parallels to a halt and prevent it from working properly-and conversely keep your VMs from working as well-stems from the multiple preference files used by the app to store configuration and settings information for both the app itself and the VMs it hosts. Parallels is not a large application, and its package-based nature makes installation a breeze for both manual and managed deployment scenarios. Macs using Parallels can create any number of virtual machines (VMs) and run them sequentially alongside the underlying macOS to take advantage of the best that all OSs have to offer. The Parallels Desktop application, better known as a hypervisor, aides computing by leveraging the hardware resources of a device to efficiently run more than one OS at the same time, from the same system.