https://help.tallysolutions.com/docs/td9rel54/td9/getting_started_with_td9/licensing/upgrade.htm

Upgrading to the Latest Tally.Developer 9 Release

Upgrading to the latest release of Tally.Developer 9 allows you to enjoy the new features introduced in the product, and access the latest Default TDL code.

To upgrade to the latest Tally.Developer 9 release

1. Go to Tally.Developer 9 installation folder in your computer.

2. Double-click the setup.exe icon in the local system.

3. Click Upgrade in the Tally.Developer 9 Installer , as shown below:

A message with the details of the latest release, if available, is displayed.

4. Click Install to upgrade to the latest release.