Jerry,
Are you using this in the "Set Installer Flag..." function?
I have created and uploaded a SetupBuilder 8 demo project. BTW, you mentioned the "SB7 Reference Manual". I would suggest to install the latest SB8 (it's free as part of your maintenance plan; we can re-send the SB8 login if you want).
http://www.lindersoft.com/projects/RestartFlag.zip
IMPORTANT: when you see the "This system must be restarted to complete the installation. Press the OK button to restart this computer. Press Cancel to return to Windows without restarting." message box, please press "Cancel" in this demo!!!!!
Does this project help?
Friedrich