i found out, that there is an error in the documentation:
see here: Windows | openHAB
In the section " Set up openHAB to run as a Windows Service"
See the wrapper example-data. In the line
wrapper.java.additional.11-Dopenhab.userdata-"%OPENHAB_HOME%\userdata"
is missing an “=”
It should be:
wrapper.java.additional.11-Dopenhab.userdata=-"%OPENHAB_HOME%\userdata"
if you correct this file, than the service is running well 
Somebody should correct the documentation…
Ralph