If you use Conditional Build Tags you may exclude topics from the build. They will still exist on the server but should not be found using Search or via the Index.
If you truly want to remove them from the server you will have to manually delete them.
To avoid any confusion in AnahidMA's mind, I hope Rick will not mind me adding something.
When you generate and publish, RoboHelp first clears any content in the folder to which you generate. However, for good reason, it does not do that when you publish to the server. Anything there remains but, as Rick says, becomes inaccessible to the user.
The files always remain in your source project, they just do not get generated and published when your layout says not to include topics with the defined build tag(s).
See www.grainge.org for RoboHelp and Authoring tips
You gentlemen are wonderful
I will read up on Conditional tags - I have not used them. This material needs a complete re-vamping, but I need the time to do so. Still - I can start doing a little at a time when I have a few minutes.
Thanks for the fast response!