Simulation:

1. Create a job called "TESTE" with the Windows command: notepad.exe
2. Start your job "TESTE", check that Notepad is started (dont close).
3. Cancel the build of the job "TESTE" and see that Notepad is still open.
4. Check the stacktrace on the server console, as attached file.

Problem:
When you cancel a build, the process that started don't closes.

Workaround:
1. Copy the file "WEB-INF\lib\winp.dll" to the directory "C:\Windows\system32" and restart the server.

PS: ProcessTreeKiller is enabled.