You need to take a data backup before upgrading to the higher releases.
To upgrade to Tally ERP 9 Release 5 follow these steps-
1. Take data backup in existing Tally.ERP 9 release.
2. Press F12: Configure > Licensing > Surrender.
3. Enter the administrator or site administrator e-mail ID and password.
4. Press Enter to surrender the license.
5. Install Release 5 in new Drive/folder.
6. Load Release 5 and reactivate the license.