Once the AES is installed, you will be able to start and stop the service from the Windows Services. The service will appear as Argentis Avatax Event Service, and the release version.   When the service runs, it will create an Event Log at the Applications and Services Logs, named Argentis You will see entries appearing, the first check is to confirm you see a log entry showing the AES connected to the SAP DI-API, like the following:   When the AES calculates taxes on a document it will create a log entry like this:   You can also see how the AES skips the calculation on events generated by any of the applications detailed in the Exclude Apps list at the AES xml configuration file.