That's a clever idea and I will keep it in reserve. I take your point about security, after all that is why they no longer show by default,
There are other client-server applications on the network using chm help, I assumed using server copies, rather than local ones. Unfortunately I have no acess to see what the local C: drives have and won't be granted any, even for a single machine. That policy makes working with them very difficult. Nobody in the current network team seems to remember how it was done for the other applications and now they are researching it at my request, I feel sort of obliged to carry on down that route, at least for the moment.
your suggestion is a good one though, so if they fail I will gratefully take it up.