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, you will get that “Access denied” error.
You can look here in order to be able to use another user whith appropriate rights.
For more information, see "Microsoft monitors" under "Monitors" section in Neoload documentation.
