How to Upgrade RouterOS?

RouterOS Beginner Basics
1

How to upgrade MikroTik RouterOS from version 3.20 to 4.0 without losing the configuration?

2

I heard that you can make a backup …

3

Detail please.

4
  1. http://wiki.mikrotik.com/wiki/Configuration_Management#System_Backup
  2. http://wiki.mikrotik.com/wiki/Upgrading_RouterOS