1. Disable your antivirus before installing Lightroom Classic. To do this, open Windows Security from the Start menu.

2. Click Manage settings.

3. Make sure to disable all of the protection features in the window.

4. Open the directory where you saved the installer, right-click on the ZIP file, and then select Extract to.

5. Open the extracted folder.

6. Right-click on the ISO file and then select Mount.

7. Double-click on autoplay.exe. If UAC (User Account Control) pops up, press Yes.

8. Hit the Install button.

9. Press Continue.

10. After the installation is completed, you can launch Lightroom Classic immediately.

11. Lightroom Classic has been successfully activated and is now ready to be used.