When I change the values of environmental variables on a windows slave and reboot it, the Windows Slaves plugin fails to detect the changes in environmental variables (example: changing the Path variable). The only way to get the windows slaves plugin to detect the changes in environmental variables is to restart the Jenkins server.

Steps to reproduce:
1. Launch a windows slave using the "Launch slave agents via Java Web Start" method.
2. Change the value of an environmental variable.
3. Reboot the windows machine acting as a slave.
4. Launch the same windows slave using the "Launch slave agents via Java Web Start" method.