Described herein are systems, methods, and software to deploy instant guest clusters in a computing environment. In one example, a host is configured to initiate startup operations of a first virtual machine and stop the startup operations prior to performing guest customization operations. The host is further configured to, in response to a request for a second virtual machine, initiate the second virtual machine as an instant clone of the first virtual machine and execute the guest customization operations for the second virtual machine based on metadata provided for the second virtual machine, wherein the metadata provides configuration information for the second virtual machine.