Workflow upgrade failed (administration service not started)

Hello,

I am new to the upgrade process and I have encountered an error while trying to upgrade my dev environment running on SharePoint 2013.

Here is the error:

Preparing files...

...

...

Detected SharePoint 2013 is installed

Installing Nintex Workflow solution...

Stopping any running Nintex Services...

Restarting Web Servers and Timer Service...

Resetting Server(s):

xxxxxAPP1

xxxxxAPP2

xxxxxWFE1

xxxxxWFE2

Stopping Timer service on server xxxxxAPP1.

Starting Timer service on server xxxxxAPP1.

Stopping Timer service on server xxxxxAPP2.

Starting Timer service on server xxxxxAPP2.

Stopping Timer service on server xxxxxWFE1.

Starting Timer service on server xxxxxWFE1.

Stopping Timer service on server xxxxxWFE2.

Starting Timer service on server xxxxxWFE2.

Installing Nintex Workflow Core Components solution...

Updating Solution Core Components

Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) is not created yet (time waiting=3 seconds) Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) is not created yet (time waiting=6 seconds) Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) in server xxxxxAPP1 is not finished yet Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) in server xxxxxWFE1 is not finished yet Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) in server xxxxxWFE2 is not finished yet Upgrade job for solution Core Components (NintexWorkflow2013Core.wsp) in server xxxxxAPP2 is not finished yet Upgrade timer job for solution: Core Components (NintexWorkflow2013Core.wsp) in server xxxxxAPP1 finished successfully at: 03/10/2017 23:36:42 Upgrade timer job for solution: Core Components (NintexWorkflow2013Core.wsp) in server xxxxxWFE1 finished successfully at: 03/10/2017 23:36:41 Upgrade timer job for solution: Core Components (NintexWorkflow2013Core.wsp) in server xxxxxWFE2 finished successfully at: 03/10/2017 23:36:41

Upgrade time job status is set to: Aborted. Error Message: The administration service job definition 'solution-deployment-nintexworkflow2013core.wsp-0' (id ce24cae5-8a2b-4383-b140-2d3203d3b6f4) was not executed because the administration service on this server is not started. This job definition can be run manually using 'stsadm -o execadmsvcjobs'.   

One or more errors were detected. Please scroll up for details.

Where do I find the administration service on the server? From the list of services I did not see it listed.