In order for the winnt or winnt32 command in the "setup" package to be run on the destination computers, it must be made available in a Run Command on Workstation job. The job is created by dragging the package to the machine group on the site and filling in the Job Details dialog that appears as a result. You might also choose to take advantage of the job scheduling and configuration options.
After you have set up the job, it appears in the Jobs window as a pending job.