Computer in console not showing client as installed

We found a handful of computers that had the ConfigMgr client installed, but the console was not reflecting this. After some investigation on an affected computer, I noticed the client certificate said "none":

This is not normal. In addition, some of the items under the Actions tab were missing. Fortunately, I found this blog post that contained the solution. 

The computer was stuck in provisioning mode. The simple fix was to change the HKLM\SOFTWARE\Microsoft\CCM\CcmExec\ProvisioingMode registry key to "false", then reinstall the ConfigMgr client.  SEE UPDATE BELOW

NOTE: The safest bet is to reimage the system in question. If the step that removes the computer from provisioning mode didn't work, it's quite possible there were other issues during imaging. But this is a quick fix if you can't reimage for some reason.

H/T Daniel Classon

UPDATE: Thank you to Microsoft MVP and all-around swell guy Nash Pherson for pointing out that the registry method does not entirely remove the computer from provisioning mode. This article shows how to do it properly via a WMI method:

Invoke-WmiMethod -Namespace root\CCM -Class SMS_Client -Name SetClientProvisioningMode -ArgumentList $false

Or, run the following from an elevated command prompt:

powershell Invoke-WmiMethod -Namespace root\CCM -Class SMS_Client -Name SetClientProvisioningMode -ArgumentList $false