I have recently started using RH 10 (was on 7 for a long time). I had a request that users wanted to combine two robohelp files into one. (We have a Front Counter Manual and a Systems Manual. They would like to combine them into one project).
Is there an easy way to do this without messing each of these projects up?
From what you have described, it would seem you are asking how to Combine projects. Certainly that may have some benefits from the authoring side, but if your users simply want to see a unified Table of Contents as if it were one large project, you might want to check out Peter Grainge's site at the link below:
Whilst my instructions are lengthy, that is to give a full explanation of all the ins and outs. In your case the work will be little more than creating a parent and setting up your two existing projects as children.
It's a lot easier than trying to have one source project.
See www.grainge.org for RoboHelp and Authoring tips