You need to add the following line to each and all your config files (If you use multi-algo-switching, what you have in the main config file is not read):
"reboot_script" : "reboot-windows.bat",
(or whatever your reboot file is called).
So for example if you have two config files...
config-normalv7.txt
config-heavy.txt
...you will need to add the line above at the bottom of each.