Problem: from within a hudson "windows batch task", my bat file in turns
invokes. e.g. a java.exe. When I terminate this hudson task with [x], the
java.exe is NOT terminated, and must be manually killed.
Quite a nasty thing, as "normal" users of the web-interface don't understand,
and the next build perhaps then fails, as the old build process still has some
files open etc.

Pls note the thread and Kohsukes last reply in
https://hudson.dev.java.net/servlets/ReadMsg?listName=users&msgNo=967

I assume that approach would solve the problem by using the windows-tool "pskill -t"
Proposal: make the "kill" command configurable in hudson, and document, how to
solve the problem. The hudson server administrator shall then download pskill
himself and configure hudson.
This way, you dont have problems with licensing.