If it doesn't work going thru the windows start menu in the imageline folder,I'm afraid your going to have to re install to make it work then....I ended up having to do that also.
Also note fl in sonar is awesome but you most likely will loose most of the typing keyboard letters functions because sonar takes them,basically you won't be able to rename things within fl studio but the other keys work,best bet is do what you can in fl studio then one you start wanting to do things in sonar then open fl as vst then open the project and go from there,works out better that way.for me anyway everyone is different