This blog explains the difference in doing post installation steps for SAP PI7.1 and PI7.3. Below screen which shows the standard installation completed successfully for Process Integration.
Log into NWA run the configuration wizard to complete post installation steps.
Click on Configuration management -->Scenarios run the configuration wizard as shown in below screen.
Select the Initial configuration select the Netweaver initial setup and click on start button as per below screen.
Follow the wizard process until all the steps completed and fill the mandatory parameters wherever required.
From PI7.3 we have different options available in the places of Netweaver initial setup to run the configuration wizard.
Log into NWA-->Configuration wizard-->Click on Functional Unit Configuration and enable required functional unit based on the type of installation.
If the installation is standard PI installation with dual stack or optional installation AEX choose functional unit from the available list as per below screen. Select the functional units and click on Enable automatically push button.
Once the functional unit is enabled you can check post installation activity runs under Running Configuration Tasks.
Follow the wizard process until all the steps completed and provide the mandatory parameters wherever required.