I have same problem with Tomcat 8 and I've found answer:
http://tomcat.apache.org/tomcat-8.0-doc/windows-service-howto.html#Installing_services
You need to execute from promt:
cd %CATALINA_BASE% -> CATALINA_BASE : C:\Program Files\ApacheTomcat\apache-tomcat-8.0.0-RC5\bin
service.bat install