Winforms accessing connectionstrings in multiple projects

Winforms accessing connectionstrings in multiple projects

I have for example 3 Winforms projects inside the same solution.
Project1
Project2
Project3
When I build the solution, all the projects and his respectives files
(.exe) are generated. The problem is: Each project uses different
connectionstring and just the solutions .config file is generated in the
Bin folder. When I deploy the solution to my customer, the project1 and
project2 (for example) shows errors regarding to connectionstring problems
(diferent Data Source, UserId and Password).
I've tried to put the connectionstring inside the .config file generated
but it's not working too.
How can I manage these connectionstrings and works well when I deploy my
programs ?
Regards
Jr