In order to get my Windows nodes to correctly kill all processes and subprocess when a build is aborted I had to make sure that all processes have a BUILD_ID environment variable, and that all nodes have hudson.util.ProcessTree.enabled=true.

The problem is that every once in a while, nodes that I had previously configured with hudson.util.ProcessTree.enabled=true will revert to false.

I'm configuring that option via Script Console in node page whenever it changes to false, and I was not able to find anything in Jenkins logs, nor the node command line (started by running java -jar slave.jar).

This problem does not occur in Unix nodes.