The ConfigMgr client has traditionally been a fairly passive component on computers. It gets policy on a schedule, it submits inventory, evaluates baselines etc but typically doesn't make any changes to the computer unless you tell it to. The ConfigMgr 2012 client has a client health process that runs every night (midnight plus an offset is the default time) and is set to automatically remediate any of the issues it is configured to check for (WMI, CM client service stopped, etc). For some environments making unplanned changes to a production computer may be worrisome and you may want to disable this auto remediation feature. If so, consider changing the following registry key on these clients:
The default value is FALSE, meaning the client will auto remediate problems when found and you can monitor this in the Monitoring workspace in the console. Change the value to TRUE if you want to adjust this behavior. When the registry entry is set to TRUE the client will not auto remediate problems that are found and administrator will see alerts in the Monitoring workspace. The administrators can then manually (or use some other process) to resolve the identified computer issue.