1) Check and see if you have JBOSS_HOME and JAVA_HOME as Environment variables. To do this open "Advanced system settings" on windows. Click on the advanced tab. On the bottom click "Environment Variables"
2) A new window will open and under System Variables click "New". A window will open enter "JAVA_HOME" and the location of the jdk.
3) Repeat the same step 2 for JBOSS_HOME variable, this time choosing the variable value for the location of jboss/wildfly.
4) Now you can run the add-user.bat file from inside the wildfly\bin folder. Open cmd and cd to the wildfly\bin and execute the add-user.bat command. Select a) Management User
5) Enter the details that are requested (See screenshot below). On the last question "About to add user 'Temp' for realm 'ManagementRealm' Is this correct yes/no? Choose yes and this user will be successfully created.
6) You can now access http://localhost-9990/console with the username created and you can now deploy/configure datasources & drivers through a UI for IDM.