A former colleague directed me to this blog posting which explains the use of AppSense Environment Manager engineering key ‘PreventUnapplyOnConfigChange’

I’d never heard of it before but soon found it detailed in AppSense Tech-Note TN-150931 (login required).

Adding this registry value solves the problem facing AppSense Administrators when making changes in a busy operational environment as it means that EM configuration files can be updated while a user is logged in with causing any problems – something that’s especially useful in the early stages of a deployment when changes are carried out all the time.

One of the headaches of managing AppSense Environment Manager environments is scheduling the deployment of configuration updates. Generally you’d only update the endpoint at restart so you ensure you don’t effect any active users. However there are a couple of obvious problems with this:

  1. any new computer start up actions added will need a second device restart before they apply
  2. you may not have control of how often endpoints are restarted so changes could take days or weeks to deploy

So if you have an environment that’s subject to constant change you’d have to consider deploying on a schedule and clearly that’s an issue if you’re working with a 24/7 operation.

Changing the EM configuration when the user is logged on can affect their session – settings configured by EM can be removed mid-session causing functional issues for the user and potentially opening security holes.

The ‘PreventUnapplyOnConfigChange’ registry setting prevents this behaviour which means that configuration updates can be applied to an endpoint while the user is logged on not taking effect until next logon.

Create the following registry value appropriate for the version of Environment Manager you have:

Environment Manager Version 8.0.x.x

HKLM\Software\AppSense Technologies\Environment Manager

Environment Manager 8.1.x.x

HKLM\Software\AppSense\Environment Manager
Registry Value Name: PreventUnapplyOnConfigChange
Registry Value Type: REG_DWORD
Registry Value Data: 1

Needless to say adding a Computer Startup  Set Value action is a simple way to get the setting deployed.
A value of 0 is the same as default behaviour if the key is not created i.e. EM actions are unapplied on config change

Note the limitations highlighted by AppSense if you’re using a persistent profile:

“If using a local or roaming profiles, using this Engineering Key would lead to these actions being applied permanently for any users logged on when a new configuration is deployed. In these circumstances, it would be preferable to only deploy configurations at computer startup (if there are actions which need to be unapplied).Self-Heal actions are currently unapplied regardless of this setting”

Thanks to Darren Randall at HP Enterprise Services for bringing Geert De Keyser’s blog entry to my attention which led me to the AppSense Tech-Note.