Neoload uses the Perfmon API to monitor Microsoft application. This API does not provide the option to set a specific username/password.
By default, the current logged in user will be used to connect to the target server. If the current user account does not have the appropriate rights, run the Controller using the appropriate account by right-clicking on NeoLoadGUI.exe and using the "Run as..." option.
Another way is to create a network drive from the Neoload controller to your target server with a user that has sufficient rights on the target server to monitor.
For example, you can run the command below from the Neoload controller.
net use \\192.168.1.1 /user:domain1\user1 Password1
1. "192.168.1.1" is the IP address of the server you want to monitoring.
2. "user1/Password1" are the credential of the user who has sufficient rights to monitor your target server.
For more information, see "Microsoft monitors" under "Monitors" section in Neoload documentation.
