
The latest version can be found on the Download page of the official product web site. The installation package is archived.
Here are the steps to accomplish:

This screen is a standard welcome and disclaimer page.
Simply press Next to proceed.
You can press Cancel anytime to abort the installation.

This screen presents the End-User License Agreement. Please read it carefully. Once you are done reading, check I agree if you agree with the terms and conditions.
Then press Next to proceed to the next screen.
You may disagree with the terms and conditions. If this is the case, abort the installation now. Past this screen, you are deemed to agree and you are bound to the terms and conditions.

This screen asks for an installation path. The standard path is provided by default.
Click Browse... to change the path.
You can ask for an estimation of the disk space the application will use by pressing Disk Cost....
When you have specified the installation folder, press Next to proceed to the next screen.

This screen allows you to confirm the installation.
Press Next to proceed to the next screen.

This screen displays a progress bar of the installation process.
Wait until the installation completes.

This screen provides the release notes of the version you installed.
Review carefully the disclaimers and the list of recent changes. There may sometimes be instructions or notices of changes that may affect your settings or activation of the ARX module.
Press Next to proceed to the next screen.

This screen simply indicates that the installation has been successful.
Press Close to close the installer.
Launch AutoCAD.

Type the command appload in the command prompt.
Type in the path to the installation folder of ObjectDCL ARX or browse to that location.
Select ObjectDCL.xx.arx, where the number matches the revision number of AutoCAD.
Press Load to load the module.
Drag and drop the module to the Startup Suite.
Repeat the same steps for ArxHelpers.lsp.
Press Close to close the dialog.

Type the command options in the command prompt.
Switch to the Files tab.
Expand the Support File Search Path.
Add the path to the installation folder of ObjectDCL ARX.

Note: This step presumes you successfully loaded the module in the appload dialog.
Switch to the ObjectDCL tab.
Press Active online to activate your copy.
Note: It is not necessary to activate your copy if you are using ObjectDCL-enabled application that were signed using the Distribution Kit.

You may get this dialog upon loading the ARX module or starting AutoCAD.
Press Activate online to activate your copy.

Type in the serial number you obtained after purchasing a license of ObjectDCL ARX online at the official ObjectDCL web site.
Type in your password two times. The password is set the first time you activate with a given serial number. Subsequent activations for that serial number will have to be completed with this exact password. Please write the serial number and password down and store it in a secure and safe place.
Press Active to proceed with the activation.
You can always uninstall the ObjectDCL ARX from the Windows® Control Panel with Add or Remove Programs. The application appears under the name of ObjectDCL ARX - Release 7.2.x.

