How to assign roles for diferents windows?

I need to implement a system in which only certain users will enter and some will be able to Edit and others only display information without being able to modify them.

Your question needs more detail.

You should look at Security: Users, Roles on the Configure Web Interface, AND in the documentation.

You need to determine how you need security broken down. How many areas of your project, and how many functions in those areas.
You probably want to define Roles such as -ViewOnly, -ViewOnly, -Operator, -Maintenance, -Administrator.
Then in the designer you can disable or hide components (including navigation components) based on the defined Roles.